MBA overheating: important new insight!

[nudos]

Hi.

Long time reader, first time poster. I've been reading all the threads about overheating. I believe I have read every single post of the debate, but I haven't seen anyone else describing what I have experienced. I therefore start this new thread as I believe the unintentional experiment that I will describe in this post will shed some light into the MBA overheating problem. If I by any chance have missed a previous post describing the same results I appologize.

First a little background describtions, bare with me, if you are interested in getting to the bottom of the MBA overheating problem I believe the read will be worth it!

When getting my week 10 MBA i cloned my MacBook CCC "fresh install" clone onto my MacBook Air. That turned out to be a bad idea since I run into a lot of problems. For instance, since the MBA lacks a ethernet port that messed up Time Machine seeing as that uses "en0" to identify the computer it is cloning. Also system preferences was messed up seeing as the MBA has a completely different trackpad than my cloned MacBook.

All these issues (and more) led to the purchase of an external DVD drive and a fresh install of Leopard from the MBA system DVD's.

The thing I discovered though, is that while I had the MB clone as my system on the MBA I had NONE of the overheating issues whatsoever. The temp was frequently around 70 Celsius, and even as high as 80 Celsius sometimes. However, I NEVER had a core shut down or any reduced performance. The fans cranked up, but that was it.

With my fresh install with the proper system for the MBA, the overheating issues have hit my unit. I now experience all the issues as described in other threads. Core shuts down, and it shuts down quickly, even at temperatures as low as 65-70 Celsius.

This difference in performance happened literally from one day to the next, and my habits or usage of my MBA have not changed from that day to the other..

With my low level of computer knowledge I would expect this to evidence that this is software related. That the MBA has set limits to what it is supposed to do, either set on purpose by Apple or set by "buggy" behaviour. These limits seem to be alterable seeing as my MB clone ran cooler and free from MB overheating issues.

Again; I believe I have read every single overheating post out there, but could not find an "experiment" like the one I unwillingly have conducted. I think this is important enough to not "get lost" in the other huge overheating threads so I started a new one. If I have missed previous posts concerning this exact issue, I appologize.

[digitalfx]

I have a fresh install from provided DVD's and experience very little heat problems. I have had the MBA since they first shipped the SSD model (ordered on launch day) and have only experienced core shut down 2-3 times, and it was always when playing video.

My MBA runs 15 hrs a day every day, and rarely do I ever even hear a noise.

[n0de]

@nudos

It seems that either people have core shut-downs or not. There are a lot of us who it never happens to when the temp is <98C. Those who do report it at lower temps seem to get their machines replaced by Apple very quickly.

I understand your point about the install - there is probably a driver on the Air install disk that does not exist in a standard MB install. But the fact that a core shuts down so quickly sounds like a defect in the hardware. I would return it for a replacement before you become disenchanted.

[nudos]

So how come the hardware wasn't affected when running the MB clone installation, but is when running the MBA installation?

The whole point here is that it's the exact same hardware, but with different OSX software. Has to point to the issue arising due to something with the combination of MBA software and MBA hardware right?

All I know is that my MBA running MB software didn't have any of the problems..

[bcaslis]

Posted this on the Apple forms also didn't you? Sorry but I've only done installs on my MBA, no cloning or migrating and I have none of these overheating issues. Sorry but this is not the reason.

[ayeying]

the earlier made MacBook airs suffered from the overheating problems mostly because of the bad thermal paste and other factors. the newer built models dont have those problems or if they do... its less and less likely.

you can't compare a recently bought MacBook air with one bought from last year.

[bcaslis]

the earlier made MacBook airs suffered from the overheating problems mostly because of the bad thermal paste and other factors. the newer built models dont have those problems or if they do... its less and less likely.

you can't compare a recently bought MacBook air with one bought from last year.

You couldn't bought one last year, they started shipping in February.

I have a week 3 so it's fairly early. Never overheated or shut down a core. And I've tried.

[Garemz]

Core shutting down for no reason

[Malcster]

Core shutting down for no reason

I doubt it, you have 'My Processes' selected at the top on Activity Monitor, if you change that to 'All Processes' you should see the process (obviously a system one.. not one of yours..) that has crashed and be able to kill it, you will also get some idea of where to look to start fixing it.

[izibo]

I doubt it, you have 'My Processes' selected at the top on Activity Monitor, if you change that to 'All Processes' you should see the process (obviously a system one.. not one of yours..) that has crashed and be able to kill it, you will also get some idea of where to look to start fixing it.

Nope... What happens is that the CPU overheats and one core shuts down for 10 seconds or so then starts back up. I had this happen to me. It was not a system issue.

I cloned my old MBA (week 2) hard drive to my new MBA (week 11) and I have no problems. This rules out a software issue.

[Malcster]

Ah, i was so busy looking at how overloaded that one core was i didn't see the fact that the other one wasn't doing anything at all! my bad.

[bcaslis]

Core shutting down for no reason

No saying this isn't authentic but something is odd. The numbers say over 66% idle, yet the picture shows one core almost maxed.

Do you have anything installed to show temperature? I use iStat Pro, it would be interesting to know what your CPU temperature is.

[bjdraw]

Something odd is going on, and I think it has to do with the graphics chip/software.

Last night I played a 720p H.264 trailer from Apple in a loop and in about 10 minutes it starts to lock up the MBA even though the CPU is only at ~65C and the utilization is about 65% averaged. Then I played a DVD, which played fine for as long as I wanted, but doesn't cause the MBA to heat up past 57C, and only uses about 5%.

But here is the kicker. If I do two instances of yes > /dev/null, although it drives up the cpu utilization to 100% and the temp up to 85C, (Yikes!) a core never shuts down and the MBA is continues to be responsive (let it run for 15 minutes). But if I play a DVD and then do the 'yes' test, within 10 minutes the core starts to shut down and the entire MBA locks up when it does. All the while, the cpu is at about 65C and 100% utilized.

So this tells me that it has something to do with the video and since I don't remember my MBA doing this when I first got it, I wonder if this has anything to do with the recent Leopard Graphics update on Feb 11th?
http://www.apple.com/downloads/macosx/apple/application_updates/leopardgraphicsupdate10.html

Anyone have a MBA without the grahics update installed that can test this theory?

[pgharavi]

Something odd is going on, and I think it has to do with the graphics chip/software.

Last night I played a 720p H.264 trailer from Apple in a loop and in about 10 minutes it starts to lock up the MBA even though the CPU is only at ~65C and the utilization is about 65% averaged. Then I played a DVD, which played fine for as long as I wanted, but doesn't cause the MBA to heat up past 57C, and only uses about 5%.

But here is the kicker. If I do two instances of yes > /dev/null, although it drives up the cpu utilization to 100% and the temp up to 85C, (Yikes!) a core never shuts down and the MBA is continues to be responsive (let it run for 15 minutes). But if I play a DVD and then do the 'yes' test, within 10 minutes the core starts to shut down and the entire MBA locks up when it does. All the while, the cpu is at about 65C and 100% utilized.

So this tells me that it has something to do with the video and since I don't remember my MBA doing this when I first got it, I wonder if this has anything to do with the recent Leopard Graphics update on Feb 11th?
http://www.apple.com/downloads/macosx/apple/application_updates/leopardgraphicsupdate10.html

Anyone have a MBA without the grahics update installed that can test this theory?

I had a core shutdown before the update.

[macsimonwoo]

anything tasks that require the processors to do more work will generate more heat and cause shut down.

i tried with Flash, with and without hardware acceleration, both shut down cores.

maybe running a DVD does not really require processor power hence no heat generated, no shut down....

[NC MacGuy]

Having read these posts for a while I tried to replicate a core shutdown on my 1.6/80. I used handbrake to encode 3 dvd's in quick succession. Never once did a core shutdown. It got mighty hot, fan spun up to 6200+/- and it encoded rather slowly from the USB Superdrive but never a shutdown. Really.

Processors were both maxed out as anyone who's used handbrake knows. For at least 4-5 hours straight. No shutdown.

Then, I took a cross country plane ride and watched the movies repeatedly until I killed the battery. No core shutdown watching vid's either. I used QT and iTunes as viewers. My Air got hot, the fan spun up to 6200 but never a shutdown. As a matter of fact, I didn't have any stuttering videos either.

My Air is a week 2 - '08 build. Maybe I got lucky but it has and is performing admirably.

[macsimonwoo]

Having read these posts for a while I tried to replicate a core shutdown on my 1.6/80. I used handbrake to encode 3 dvd's in quick succession. Never once did a core shutdown. It got mighty hot, fan spun up to 6200+/- and it encoded rather slowly from the USB Superdrive but never a shutdown. Really.

Processors were both maxed out as anyone who's used handbrake knows. For at least 4-5 hours straight. No shutdown.

Then, I took a cross country plane ride and watched the movies repeatedly until I killed the battery. No core shutdown watching vid's either. I used QT and iTunes as viewers. My Air got hot, the fan spun up to 6200 but never a shutdown. As a matter of fact, I didn't have any stuttering videos either.

My Air is a week 2 - '08 build. Maybe I got lucky but it has and is performing admirably.

do you mind try this? go youtube.com watch this video
http://www.youtube.com/watch?v=Ar_r2kE9Ej4

1. watch this full screen, it must be full screen
2. if the first time your core did not shutter, try a 2nd time
3. check your temperature

feedback your temperature and let us know if your video stutters ? thanks!

[hotsauce]

do you mind try this? go youtube.com watch this video
http://www.youtube.com/watch?v=Ar_r2kE9Ej4

1. watch this full screen, it must be full screen
2. if the first time your core did not shutter, try a 2nd time
3. check your temperature

feedback your temperature and let us know if your video stutters ? thanks!

Watched it twice. CPU temp 139 and Fan about 4500 rpm. Can't get it to stutter. I'm using a 1.6/80/wk3 btw. What's with that guys laugh anyway?

[NC MacGuy]

do you mind try this? go youtube.com watch this video
http://www.youtube.com/watch?v=Ar_r2kE9Ej4

1. watch this full screen, it must be full screen
2. if the first time your core did not shutter, try a 2nd time
3. check your temperature

feedback your temperature and let us know if your video stutters ? thanks!

Hilarious. Ballmer is a clown. Vista? Gimme' a break. DVD's, did he ever hear of flash drives? Ballmer makes me appreciate & miss Gates.

On the vid technically speaking:
No, not once did it stutter - full screen. Temp at completion = 68ºC, fan 3300 rpm. I also had open Adobe Reader, Word, iCal, Mail.

[hotdamn]

you give me hope, Larry David.

also that Video is brilliant!

[Scott6666]

I have been on the overheating forums ever since the MBA came out. I have often pondered how a 20W CPU could get hotter than a 35W MBP cpu. I am beginning to wonder what the heat envelope of the GPU really is.

That would explain why things like DVD ripping do not drive the fan/stutter but playing video does.

The MBA uses only one fan and one heatsink. Maybe the CPU is not at fault but the GPU is. I noticed previous poster had a similar theory.

Now I know it may not directly explain core shutdowns; could be a separate defect or just that the GPU generates enough heat to impact the CPU.

Anyone want to voice support or refute?

[NC MacGuy]

I have been on the overheating forums ever since the MBA came out. I have often pondered how a 20W CPU could get hotter than a 35W MBP cpu. I am beginning to wonder what the heat envelope of the GPU really is.

That would explain why things like DVD ripping do not drive the fan/stutter but playing video does.

The MBA uses only one fan and one heatsink. Maybe the CPU is not at fault but the GPU is. I noticed previous poster had a similar theory.

Now I know it may not directly explain core shutdowns; could be a separate defect or just that the GPU generates enough heat to impact the CPU.

Anyone want to voice support or refute?

A standard format and viewer would probably help in testing theory.

I've seen complaints using DIVX, Flash, VLC, F1V, WMV, AVI's?? Someone else complained using the ABC vid viewer - whatever that is. I wouldn't download it. I tend to stick to QT and mp4 formats and have had luck. I can also watch utube vid's with heat but no stutter.

For kicks, I tried watching a vid while using Handbrake. It worked, did stutter a bit but was playable for about ten minutes then I lost my nerve. Serious proc. loading w. GPU and still couldn't get a core to shutdown.

I went through the RSS w. an old MB and wanted darn well to find a problem w. my Air if one existed since I don't buy Applecare.

[digitalfx]

no overheating here either...I can watch any movie I like.

1.8/SSD

[ayeying]

do you mind try this? go youtube.com watch this video
http://www.youtube.com/watch?v=Ar_r2kE9Ej4

1. watch this full screen, it must be full screen
2. if the first time your core did not shutter, try a 2nd time
3. check your temperature

feedback your temperature and let us know if your video stutters ? thanks!

Temps averaged at 60-65 deg C, fans went to 6200rpm but it did not studder. Had VMWare Fusion w/ Vista running along with iTunes, Quicktime, firefox, entourage and word opened (running also w/ at least 1 window)

[pughchrism]

watched this vid 2x - week 11 1.6/80g up to 80C, no stuttering, no core shutdown.

however i saw a core cutting in and out earlier today at ~ 69C w/you tube and with a lost high def episode playing full screen. at first the temp inched up to 84C w/no core probs but later temp dropped down to ~ 69C and intermittent core stoppage occurred at that low temp.

a core cutting in and out at such a low temp, think i need an exchange (bought saturday)?

[Evangelion]

I have been on the overheating forums ever since the MBA came out. I have often pondered how a 20W CPU could get hotter than a 35W MBP cpu. I am beginning to wonder what the heat envelope of the GPU really is.

I don't have any numbers, but I would say that the NVIDIA-GPU in MBP runs a lot hotter than the Integrated Intel "GPU" in MBA does....

The thing you need to keep in mind is that while the CPU in MBA might run cooler than the one in MBP does, it's also housed in a a lot more tightly packed computer than the CPU in the MBP is. If you have more space, you have more room for the air to circulate and you can have bigger heatsinks and fans.

[Tom J]

...I am beginning to wonder what the heat envelope of the GPU really is. That would explain why things like DVD ripping do not drive the fan/stutter but playing video does. The MBA uses only one fan and one heatsink. Maybe the CPU is not at fault but the GPU is. I noticed previous poster had a similar theory. Now I know it may not directly explain core shutdowns; could be a separate defect or just that the GPU generates enough heat to impact the CPU.

The thing you need to keep in mind is that while the CPU in MBA might run cooler than the one in MBP does, it's also housed in a a lot more tightly packed computer than the CPU in the MBP is. If you have more space, you have more room for the air to circulate and you can have bigger heatsinks and fans.

And therein lies the crux of this issue. The rapid heating that users are reporting leads me to believe that the thin sheet of aluminum that serves as a heat sink doesn't have the mass to wick away the heat.

[n0de]

The GPU point is a really good one. The other part of the GPU is that it has the ability to throttle itself to save battery power. In windows there are user accessible controls to adjust this, not in OSX. I wonder if it's settings are too conservative.

[ayeying]

The GPU point is a really good one. The other part of the GPU is that it has the ability to throttle itself to save battery power. In windows there are user accessible controls to adjust this, not in OSX. I wonder if it's settings are too conservative.

If GPU's at fault, wouldn't 4 hours playing X2 - The Threat or Civilization 4 start causing the system to overheat, core shutdown, and all the other stuff?

[pughchrism]

watched this vid 2x - week 11 1.6/80g up to 80C, no stuttering, no core shutdown.

however i saw a core cutting in and out earlier today at ~ 69C w/you tube and with a lost high def episode playing full screen. at first the temp inched up to 84C w/no core probs but later temp dropped down to ~ 69C and intermittent core stoppage occurred at that low temp.

a core cutting in and out at such a low temp, think i need an exchange (bought saturday)?



come on pls, any comments?

[bjdraw]

come on pls, any comments?

This is the same thing I'm experiencing. No idea if it means the unit is defective.

[Eidorian]

* Last Modified on: January 29, 2008
* Article: 307297

Issue or symptom

3D graphics applications may be less responsive, or exhibit slow or 'sluggish' performance, when the CPU has been in heavy use for prolonged periods of time or in an extremely hot environment for a period of time.

This may happen if your MacBook Air is attempting to protect itself from overheating by shutting down one core of your CPU. In extreme conditions, the MacBook Air may also reduce the clock rate of the remaining core. Either protective measure may cause the application, especially 3D graphics applications, to be less responsive.
Products affected

* MacBook Air

Solution

To improve responsiveness in warm conditions, move your computer to a cooler area, or consider using a laptop cooling pad to dissipate the heat.I'm just making sure that you guys know that Apple made a knowledge base article on this. I have no clue why they removed it though.

http://www.google.com/search?q=eidorian+core+shutdown

[bjdraw]

I agree, I think it is a GPU issue.

To anyone not having this problem, try this for 15 minutes.

Download any 720P h.264 video from Apple.com/trailers
Play the movie and under the view menu, choose loop, to get the trailer to play over and over again.

Open two terminal windows and type this command in each.
yes > /dev/null
(this does nothing more than drive processor utilization to 100%)
hit ctrl+c when you're ready to quit or close the terminal window.

My system can run without any issue as long as I want at full CPU utilization, as long as there isn't any video playing. If there is any video playing, then after about 15 minutes the system starts to lock up every few seconds. (A core doesn't always shutdown, but something it does. I'm not sure why this is.)

[Scott6666]

I agree, I think it is a GPU issue.

To anyone not having this problem, try this for 15 minutes.

Download any 720P h.264 video from Apple.com/trailers
Play the movie and under the view menu, choose loop, to get the trailer to play over and over again.

Open two terminal windows and type this command in each.
yes > /dev/null
(this does nothing more than drive processor utilization to 100%)
hit ctrl+c when you're ready to quit or close the terminal window.

My system can run without any issue as long as I want at full CPU utilization, as long as there isn't any video playing. If there is any video playing, then after about 15 minutes the system starts to lock up every few seconds. (A core doesn't always shutdown, but something it does. I'm not sure why this is.)

You say it runs at full CPU utilization. I assume though the fan is pegged at 6200?

[JoeG4]

While it is true that they shrunk the CPU's packaging physically, the heat plate is still the same size, and the part that generates the most heat is also still the same size :)

[bjdraw]

You say it runs at full CPU utilization. I assume though the fan is pegged at 6200?

Yes of course, but the MBA runs as long as I want like this, as long as I don't have any video playing.

[SubZer0]

I agree, I think it is a GPU issue.

To anyone not having this problem, try this for 15 minutes.

Download any 720P h.264 video from Apple.com/trailers
Play the movie and under the view menu, choose loop, to get the trailer to play over and over again.

Open two terminal windows and type this command in each.
yes > /dev/null
(this does nothing more than drive processor utilization to 100%)
hit ctrl+c when you're ready to quit or close the terminal window.

My system can run without any issue as long as I want at full CPU utilization, as long as there isn't any video playing. If there is any video playing, then after about 15 minutes the system starts to lock up every few seconds. (A core doesn't always shutdown, but something it does. I'm not sure why this is.)

1st - I do not own the MBA, nor do I own a Mac.

HOWEVER, I am doing some research because I am soon to be a convert. SO, let me ask this - Is there a utility that measures the temp of the Graphics and Memory Controller Hub (GMCH)?

It sure sounds like the problem occurs most often when people play video, so if the GMCH is overtemping then maybe that causes the Core to shutdown. What do you think?

Mark

[droppedd]

OK i'm pretty sure it's something GPU related, at this point. I'm on my second MBA (first one had even worse problems when cores would drop and cause lockups), and i can run "yes test" from a cold boot for an hour with no core drop... but once the machine is warmed up, running an HD trailer (or two, if you want to see it happen faster), or more tellingly running a Tremulous timedemo, causes a total core drop. Once the core drop happens, it's pretty quick to reproduce if you only let the computer rest again for a few minutes, but the temp of the CPU seems to have little or no bearing on when it happens. And being hooked up to an external monitor makes it happen quicker still.

I'll do a little more research, and if I'm coming up with reproducible results I'll upload my Tremulous files and instructions to test it yourself (i'd expect 10-30 minutes of playing any OpenGL based game would probably give you similar results, if anyone can confirm that). I might even do a wipe of my MBA tomorrow to test if the Leopard Graphics update might have something to do with it.

This would be a lot easier to test, also, if there was just a way to make XBench loop its openGL test infinitely... i might whip up an applescript for that, as it's much smaller and easier to run (although unlike the Tremulous test doesn't really test any real world application).

Basically it comes down to this: I want to be able to know I can plug my Air into my TV and watch a full-length H.264 movie I bought off iTunes, or that I can play a round or two of Quake 3. If a core drops and video starts to stutter after anything less than a few hours of doing that, at room temperature on a desk, then my $1800 air is just plain junk.

Core dropping should be protection in the case you're doing something outright wrong, like using the Air in 120 degree weather in direct sunlight, or blocking the exhaust vents with something -- it should never, ever, ever happen just because you're "working it really hard". I bought a dual core 1.6 ghz intel -- not an effectively 1.6 ghz single-core only usable as dual core when i'm not doing anything with the GPU.

[Maui19]

I have been having some overheating problems. Basically, when I view youtube vids for any length of time, the temp climbs, the fans max out, and the video stutters. The temp will stay high and the fans will stay on until I reboot the computer--even if I shut down all the apps and do nothing.

The interesting thing is this: I only get this behavior when my MBA is plugged in (even if the battery is fully charged before I start).

I'm taking it in to see the genius tomorrow.

[pughchrism]

my week 11 1.6/80g is doing exactly the same thing. I did a clean install yesterday and then let it update. this made no difference.

core shutting down for 1 sec and then on for 2-3 sec at 69C when under load.

should i exchange for a new unit?

[bjdraw]

I just called Apple and reported the problem. The gentleman seemed very responsive and was very appreciate of my troubleshooting steps to reproduce the problem.

I suggest everyone call in and report the issue with the steps to reproduce the issue. The more who report it, the better chance Apple will take the reports seriously.

[bjdraw]

I'll upload my Tremulous files and instructions to test it yourself (i'd expect 10-30 minutes of playing any OpenGL based game would probably give you similar results, if anyone can confirm that).

Please do, I'd like to try to reproduce it.

[jont-fu]

I agree, I think it is a GPU issue.

To anyone not having this problem, try this for 15 minutes.

Download any 720P h.264 video from Apple.com/trailers
Play the movie and under the view menu, choose loop, to get the trailer to play over and over again.

Open two terminal windows and type this command in each.
yes > /dev/null
(this does nothing more than drive processor utilization to 100%)


Ok, I was interested in this issue and did the procedure.
1) First looped Speed Racer 720p trailer for 30min. Some programs running in the background (Azureus downloads, Safari). No stutter in video, cpu temp in the 60-65 range. Cpu utilisation about 50%.

2) Added the "yes > /dev/null" windows, maxing out the processor usage. CPU temp raised to 85C max, then settled back to around 75C. Kept this running for over half an hour. No core shutdowns (according to activity meter on dock), no stutter or noticeable frame drops. EXCEPT FOR: When Time Machine did it's hourly backup, the video playback dropped frames and stuttered occasionally. After the backup completed, video did run smoothly.

So, if I'm ever going to have an occasion where I need to simultaneously do some heavy calculation AND watch an HD video on my Air, I should turn off Time Machine. I guess it is a system process and takes precedence over user processes like Quicktime, and this causes the stutter.

YouTube videos take up about 40% CPU, which is only a bit less than 720p Quicktime! Last night I watched a 1.5GB DivX movie in VLC player which took only 20% CPU, and the fan kept silent all the time.

My MBA is 1.6 & 80, week 07 model. The only problem with this unit is a fault in the display panel (light spots "burn" momentarily on the screen), and I'm a bit afraid to take it back.. Will they take it in for a month to repair (I would miss my baby!), or will I get a new unit with possible overheating problem? Fingers crossed.

I really hope you get your overheating issues solved, and hope that my experiment was helpful.

Edit: I don't have an external display or TV, so couldn't test with them.

[ScottFitz]

I haven't done much research on this, but my experience with windows builds from previous years is this issue sounds like someones' doing some overclocking with the MacBook Air. Maybe when the OP clones his macbook, he used "normal" settings. When he reinstalled the MBA software, then maybe the overclocking settings returned?

Sounds like a GPU issue for sure if it only happens on videos. I've overclocked a lot of video cards in my days. Sure sounds like similar problems I would have when I was cranking a bit too high and had a bit too much heat to deal with.

[rom]

Folks - try transferring files to an external drive and see how fast the MBA shuts down a core. Doing Time Machine with a large update also does this.

[ayeying]

Folks - try transferring files to an external drive and see how fast the MBA shuts down a core. Doing Time Machine with a large update also does this.

None. I have a time machine backup hooked up to my network at home. it's backed up every hour, on the hour as long as im connected to the network. I would be playing some games and it still wouldn't shut down a core.

Everyone's still missing the point, if it is a GPU problem, just test it in some games and it SHOULD happen regardless of what OS you're running.

[pgharavi]

None. I have a time machine backup hooked up to my network at home. it's backed up every hour, on the hour as long as im connected to the network. I would be playing some games and it still wouldn't shut down a core.

Everyone's still missing the point, if it is a GPU problem, just test it in some games and it SHOULD happen regardless of what OS you're running.

Peggle causes my core to shut down, sometimes faster than other times.

[bjdraw]

Ok, I was interested in this issue and did the procedure.
1) First looped Speed Racer 720p trailer for 30min. Some programs running in the background (Azureus downloads, Safari). No stutter in video, cpu temp in the 60-65 range. Cpu utilisation about 50%.

Thanks so much for taking the time to be our control! But just to be clear. You are saying the video plays back perfectly? No dropped frames? Because my 1.6/80 won't play 720p h.264 trailers without dropping frames, it isn't enough to bother me, but it does drop 'em.

2) Added the "yes > /dev/null" windows, maxing out the processor usage. CPU temp raised to 85C max, then settled back to around 75C. Kept this running for over half an hour. No core shutdowns (according to activity meter on dock), no stutter or noticeable frame drops. EXCEPT FOR: When Time Machine did it's hourly backup, the video playback dropped frames and stuttered occasionally. After the backup completed, video did run smoothly.

Interesting, I assume you are on the latest version of OS X? Your temperature does the same thing mine does, but mine does drop out after about 10-15 minutes.

My MBA is 1.6 & 80, week 07 model.

I really hope you get your overheating issues solved, and hope that my experiment was helpful.


What do you mean 07 model?
Thanks again for the help.

[droppedd]

OK - here's a good but realistic stress test... once the MBA is running hot, if i start an itunes playlist and turn on the iTunes visualizer in Large mode, resize it to take up most of the screen, then wait 30-60 seconds, a core starts dropping (at least hooked up to my external monitor), and within 5 minutes one core is just totally black.

Conditions: fully charged battery, starting with a warmed up MBA (fan already spinning at 6200 RPM, like mine always is once it's been on for a few minutes while plugged in to a monitor), plugged in to 1920x1080 LCD, keyboard, and external HDD. Clamshell mode, but with lid opened (that is, the built-in LCD is off but the MBA is open for better venting/air circulation).

I'll try it later tonight under "ideal conditions" (cold boot with no external devices or multitasking) and clock how long a core drop takes. One thing i'm noticing is that it's much harder for me to get a core drop when I'm not plugged in to an external monitor, though i'll test it both ways in "lab conditions" tomorrow night.

The advantage to this test is that it's testable on an out-of-the-box MBA, with no extra 3rd-party software required, and under a realistic task ("loop several HD trailers" can take a while and sounds weird to explain to a Genius). Try it with a quicktime HD trailer or YouTube video looping on top, or Google Earth in Tour mode if you want to really make it happen fast.

Is there anyone with this problem who has bootcamp installed who can check if the same thing happens in XP or Vista?

It's also possible that there's more than one heat issue in play here. A lot of parts in the Air are in really close proximity, so working the HDD really hard while maxing the CPU could cause the same sorts of problems (eg sometimes i get core drops with nothing but Transmission and YouTube)... but i'm finding it easiest to force with GPU-taxing operations. Let's keep working to make this as easily reproducible as possible. if anyone has other ideas, keep 'em coming.

[ayeying]

Peggle causes my core to shut down, sometimes faster than other times.

Well, since i'm on my lunch break and im bored, i booted into XP, fired up Sins of a solar empire and left civ4 running in the background, the system got insanely hot (the casing itself), cpu reads at 85 deg C both cores, yet, performance did not slow down 1 bit. Ran it for about an hour, still same performance. I highly doubt a little animation would kill one of the CPU cores when 2 high 3d games can't.

[Alkiera]

I haven't had time to go to hulu.com or anything to try 720p video; most of my video is downloaded at slightly lower quality than that. I have noted it taking awhile longer to cool back off once it gets worked up, but haven't had the 'core dropping' effects some have commented on; even when watching YouTube videos for extended periods.

If I can remember some time when I've got a network connection, I'll give hulu a shot...

And by Week 07, he's refering to the week code that is in the machine serial number. Like mine, his starts W8807. W8 is some sort of product code, 8 is year(2008), and 07 is week 07, either Feb 10-16, or Feb 17-23, depending on how they count. I'd be surprised if it's 17-23, however, as I bought it on the 18th, since I was out of work for President's Day.

[pughchrism]

http://forums.macrumors.com/showthread.php?t=457887 click on this link to a thread i posted last night about thermal issues and the processor in the 1.6 mba.

i can understand that these mba's won't, nor were they designed to, be graphics intensive machines. however, i don't want my cores shutting down unnecessarily.

if they started shutting down at >90C or something then that is a good thing to protect the cores and increase longevity of these components by limiting heat stress.

i can't see any reason why overloading the cores--w/o a resultant high heat--should be set to shut the cores down. i don't believe overloading a core w/o a resultant high heat is any danger to any components. it's just a faulty setting by apple. it is not inherent to this intel processor but is caused by a setting from apple.

[bjdraw]

The advantage to this test is that it's testable on an out-of-the-box MBA, with no extra 3rd-party software required, and under a realistic task ("loop several HD trailers" can take a while and sounds weird to explain to a Genius).

What's unrealistic about wanting to watch a HD movie for more than 10 minutes? The point of the loop is simply to have a good known video clip in the way of trailers from Apple.

[bjdraw]

After a few have posted here indicating that they are unable to reproduce my test, I went to the Apple store and tried it on a demo and sure enough it runs fine.

This convinces me that there is something wrong with mine. So I'll be taking it into the genius bar. It might take me a few weeks before I can afford to not have a laptop for a week, so I'm not sure when I'll do it, but either way I'll report back.

[NC MacGuy]

After a few have posted here indicating that they are unable to reproduce my test, I went to the Apple store and tried it on a demo and sure enough it runs fine.

This convinces me that there is something wrong with mine. So I'll be taking it into the genius bar. It might take me a few weeks before I can afford to not have a laptop for a week, so I'm not sure when I'll do it, but either way I'll report back.

Hopefully they'll take care of it in quick order. I tried like heck to get mine to have a shutdown and it just won't.

Really am interested in what/how Apple rectifies your problem.

[pgharavi]

Well, since i'm on my lunch break and im bored, i booted into XP, fired up Sins of a solar empire and left civ4 running in the background, the system got insanely hot (the casing itself), cpu reads at 85 deg C both cores, yet, performance did not slow down 1 bit. Ran it for about an hour, still same performance. I highly doubt a little animation would kill one of the CPU cores when 2 high 3d games can't.

That's insane. If you download the 60 minute free Peggle demo for OSX, run it in demo mode, and see if it causes a core to shut down in OSX.

We could have a great comparison right here.

[pgharavi]

Hopefully they'll take care of it in quick order. I tried like hack to get mine to have a shutdown and it just won't.

Really am interested in what/how Apple rectifies your problem.

You're telling me that if you watch a 720p mkv or even a standard res xvid video (for 30-60 minutes) a core WILL NOT shut down on you?

[NC MacGuy]

You're telling me that if you watch a 720p mkv or even a standard res xvid video (for 30-60 minutes) a core WILL NOT shut down on you?

That's exactly what I'm saying. It gets plenty hot, fans crank but haven't had a core shutdown on me yet.

[pgharavi]

That's exactly what I'm saying. It gets plenty hot, fans crank but haven't had a core shutdown on me yet.

The only time I can get away w/out a core shutdown while watching video is IF I leave the underbelly exhaust exposed. This means propping my MBA on the edge of the chair or desk. Then I have been able to watch 720p mkvs as well as standards xvids, and even iTunes videos.

Otherwise, a core will shut down.

[NC MacGuy]

The only time I can get away w/out a core shutdown while watching video is IF I leave the underbelly exhaust exposed. This means propping my MBA on the edge of the chair or desk. Then I have been able to watch 720p mkvs as well as standards xvids, and even iTunes videos.

Otherwise, a core will shut down.

I don't know what to tell you. The exhaust vents are there for a reason. When I hear the fans start cranking, I make sure there are no restrictions to the cooling vents. Depleted a battery watching vid. after vid. on a cross-country flight last week w. no problem.

[pgharavi]

I don't know what to tell you. The exhaust vents are there for a reason. When I hear the fans start cranking, I make sure there are no restrictions to the cooling vents. Depleted a battery watching vid. after vid. on a cross-country flight last week w. no problem.

Some people have reported that not keeping the MBA plugged in (i.e. running off only battery power) keeps it cooler as well.

Can you confirm that you have watched videos for a lengthy time w/ the power as well? Thanks.

[bjdraw]

I've done all my tests with the unit plugged in, but it was fully charged.

But I do agree with NC MacGuy, if you are having problems 'cause your vents are covered, you don't have a leg to stand on.

[ayeying]

That's insane. If you download the 60 minute free Peggle demo for OSX, run it in demo mode, and see if it causes a core to shut down in OSX.

We could have a great comparison right here.

I downloaded the demo and ran it throughout the 60 minutes after I got home. Still no core shutdown. After the demo, I converted 2 AVI files to MP4 using iSquint, while keeping parallels running in the background, just not doing anything.

Edit: I should add that I run everything in clamshell mode at home. So if anything should shutdown the core, this should. Temps hovered at 85 deg C max w/o external cooling or 80 deg C with external cooling.

[hotdamn]

I can't videochat on mine at all, neither Skype nor iChat. it will stutter like hell.

also, I've had 3 core shutdowns by now.

I am a sad panda :(

[rom]

None. I have a time machine backup hooked up to my network at home. it's backed up every hour, on the hour as long as im connected to the network. I would be playing some games and it still wouldn't shut down a core.

Everyone's still missing the point, if it is a GPU problem, just test it in some games and it SHOULD happen regardless of what OS you're running.

How big are your hourly Time Machine updates? Try putting in a 2GB file that will be backed up and then transfer another 1GB whilst this is (Time Machine) is backing up.

[NC MacGuy]

How big are your hourly Time Machine updates? Try putting in a 2GB file that will be backed up and then transfer another 1GB whilst this is (Time Machine) is backing up.

I backed up my whole 53G on a fresh HD w. time machine two weeks ago and never had a core shutdown. I think if your cores are shutting down, you should be talking to the Apple barely-geniuses w. problem demonstration. I know it's hard for those who have the problem to believe there are those who don't but it's true in my case. Really.

I'm likening this to the old random shutdown syndrome of gen. one MBs. Some had it, some didn't. I did get one of those RSS gems and it was frustrating.

[rom]

I backed up my whole 53G on a fresh HD w. time machine two weeks ago and never had a core shutdown. I think if your cores are shutting down, you should be talking to the Apple barely-geniuses w. problem demonstration. I know it's hard for those who have the problem to believe there are those who don't but it's true in my case. Really.

I'm likening this to the old random shutdown syndrome of gen. one MBs. Some had it, some didn't. I did get one of those gems and it was frustrating.

I think it is Safari that is giving me the problem.

I tried running the Speed Racer 720p Trailer for 20 minutes with Mail.app and Mailplane running in the background - no shutdown whatsoever. I did start from 2500rpm and it shot up to 6200rpm after around 10 minutes. All these at 31C weather here in Manila, Philippines.

Doing this with Safari running in the background - no dice.

I still cannot see the need to bring it to an Apple Genius since I know the MBA is not defective, at this point. The weather (hot and humid in full summer temperatures and expected to rise) is partly to blame -- no, I do not have air-conditioning. :)

[rom]

do you mind try this? go youtube.com watch this video
http://www.youtube.com/watch?v=Ar_r2kE9Ej4

1. watch this full screen, it must be full screen
2. if the first time your core did not shutter, try a 2nd time
3. check your temperature

feedback your temperature and let us know if your video stutters ? thanks!

Did this twice as well - no shutdown but I was using Firefox 3 beta 4 instead of Safari 3.1. Did this with Safari 3.1 and one core did shutdown.

[macsimonwoo]

guys...i have been trying these few days..some insights..

1. room temperatures matter (with air flow or not)
i did this in a room where there is no air flow..meaning in a room, no air con, no fan blowing...core shut down. But when i did the experience in an air con room, the core does not shut down.

2. MBA uses processor power when it is downloading youtube. So if you load a youtube and view at the same time as compared to viewing a youtube when it has been loaded, there is a difference in heat dissipation. The former dissipate more. So my suggested experiment is better when you load the same movie twice from the start.

3. I believe the browser used matters.
I uses FireFox Beta 4.

4. Playing a video with magsafe power plugin and without plugin has a effect on cpu temperature.

For NC MacGuy who has did the experiment, i would say his MBA condition of Temp at completion = 68ºC, fan 3300 rpm is very good. cuz mine will surely go up to 6200 when playing youtube video full screen. May I know which country you from?

[NC MacGuy]

guys...i have been trying these few days..some insights..

1. room temperatures matter (with air flow or not)
i did this in a room where there is no air flow..meaning in a room, no air con, no fan blowing...core shut down. But when i did the experience in an air con room, the core does not shut down.

2. MBA uses processor power when it is downloading youtube. So if you load a youtube and view at the same time as compared to viewing a youtube when it has been loaded, there is a difference in heat dissipation. The former dissipate more. So my suggested experiment is better when you load the same movie twice from the start.

3. I believe the browser used matters.
I uses FireFox Beta 4.

4. Playing a video with magsafe power plugin and without plugin has a effect on cpu temperature.

For NC MacGuy who has did the experiment, i would say his MBA condition of Temp at completion = 68ºC, fan 3300 rpm is very good. cuz mine will surely go up to 6200 when playing youtube video full screen. May I know which country you from?

Just tried it again to verify - jeez I hate that Ballmer guy... Checked immediately after and sure enough, 69C and fans at 3600 this time. Close enough for experimental error.

I'm located in the lovely US of A.

[dzhiurgis]

Hey, dunno if anyone noticed this, but according to instruction manual MacBook Air comes with special - "MacBook Air ONLY" OS X DVD. Maybe after migrating some system files are transfered causing the meltdown? :rolleyes:

[rom]

Hey, dunno if anyone noticed this, but according to instruction manual MacBook Air comes with special - "MacBook Air ONLY" OS X DVD. Maybe after migrating some system files are transfered causing the meltdown? :rolleyes:

Doubt it since I re-installed my OS using the MBA DVDs.

[ayeying]

How big are your hourly Time Machine updates? Try putting in a 2GB file that will be backed up and then transfer another 1GB whilst this is (Time Machine) is backing up.

Redone my entire HDD backup of about 48GB size. Transferred the entire User Folder to my other hdd also just for this test (user folder size is 29gb) at the same time. No core shut downs. Another kicker, I left Joost running and watched a few music videos while this 30+ minute long transfer was going. Fans went a little fast at 5000+ rpm but no core shut downs.

[Scott6666]

guys...i have been trying these few days..some insights..

1. room temperatures matter (with air flow or not)
i did this in a room where there is no air flow..meaning in a room, no air con, no fan blowing...core shut down. But when i did the experience in an air con room, the core does not shut down.

2. MBA uses processor power when it is downloading youtube. So if you load a youtube and view at the same time as compared to viewing a youtube when it has been loaded, there is a difference in heat dissipation. The former dissipate more. So my suggested experiment is better when you load the same movie twice from the start.

3. I believe the browser used matters.
I uses FireFox Beta 4.

4. Playing a video with magsafe power plugin and without plugin has a effect on cpu temperature.

For NC MacGuy who has did the experiment, i would say his MBA condition of Temp at completion = 68ºC, fan 3300 rpm is very good. cuz mine will surely go up to 6200 when playing youtube video full screen. May I know which country you from?

I dunno. A computer should not be this much trouble that you have to figure out under what condition can you do "normal things" and be OK and under what conditions you can't. Unless you get it completely caught up on a blanket (or bedspread or whatever soft) and totally block all the vents it should just work.

If Steve had promoted the MBA as "really thin, but really loud with applications that stutter sometimes; but really really thin so you can live with all that crap and suck it up because although it doesn't work well, it is after all really really really thin" I doubt he'd have so many converts. Our thin computer can have compromises on speed and hard disk space, OK, but not basic usability.

Now, you know I'm right. Don't flame me.

[NC MacGuy]

I dunno. A computer should not be this much trouble that you have to figure out under what condition can you do "normal things" and be OK and under what conditions you can't. Unless you get it completely caught up on a blanket (or bedspread or whatever soft) and totally block all the vents it should just work.

If Steve had promoted the MBA as "really thin, but really loud with applications that stutter sometimes; but really really thin so you can live with all that crap and suck it up because although it doesn't work well, it is after all really really really thin" I doubt he'd have so many converts. Our thin computer can have compromises on speed and hard disk space, OK, but not basic usability.

Now, you know I'm right. Don't flame me.

u r relee smrt but r knot write.

Mine works just fine. Too much credence given to a few that have problems and the ones that do work well are labeled aberrations.

If they don't work okay, send them back and get a MB or Dell.

[rom]

Redone my entire HDD backup of about 48GB size. Transferred the entire User Folder to my other hdd also just for this test (user folder size is 29gb) at the same time. No core shut downs. Another kicker, I left Joost running and watched a few music videos while this 30+ minute long transfer was going. Fans went a little fast at 5000+ rpm but no core shut downs.

Wow! Must really be the weather here in Manila.:D

[Tensakun]

As someone seriously pondering an MBA purchase soon, am a bit worried about these overheating/performance issues.

On a slightly different tangent...has anyone actually used the MBA for long periods on their lap, that is, as a real laptop? A very large portion of my use would be on trains, sitting on top of my chinos or jeans (no thick wool skirt).

Any insight appreciated:)

[NC MacGuy]

As someone seriously pondering an MBA purchase soon, am a bit worried about these overheating/performance issues.

On a slightly different tangent...has anyone actually used the MBA for long periods on their lap, that is, as a real laptop? A very large portion of my use would be on trains, sitting on top of my chinos or jeans (no thick wool skirt).

Any insight appreciated:)

I've used mine on my lap and it's hands down the coolest running laptop I've ever owned. The Air does put the "lap" back in laptop. Proc. temps. avg. in the 40ºs C so the case is a bit cooler. Used for up to 3 hours w. thin pants in lap without noticeably uncomfortable heat.

[hotdamn]

ok guys, don't blame me if this doesn't work for you, but I called Apple yesterday, and the very charming customer rep told me to do a permission repair.
Why didn't I think of that myself - all my issues seem to be solved now.

[ayeying]

ok guys, don't blame me if this doesn't work for you, but I called Apple yesterday, and the very charming customer rep told me to do a permission repair.
Why didn't I think of that myself - all my issues seem to be solved now.

Highly doubt it is that, but if it works, hey, its something.

[Greatbug]

This is what I see after looping 2 480p trailers and 2 'yes test' for about 10 minutes:




Are these 1-second gaps a core shutdown? hardly seems worth it. . .

[hotdamn]

Highly doubt it is that, but if it works, hey, its something.

trust me, if anyone is doubting that, it's me, I am still waiting for it to shutdown/act weird. any minute now.

[jont-fu]

Some new insight on the heat issue:

I connected my external sound card (Edirol UA-4fx, very basic one) to the MBA, and now the fan speed seems to go up even when doing very light tasks.

Previously my Air was very quiet, fan keeping steady at 2500rpm when doing the same kind of tasks.

It seems that the temperature goes easily higher when connecting external gear: monitors, sound boards, etc. So the heat issue might not be with the processor but the integrated chipset, with display/communication controllers. Some users here reported core shutdowns even when the CPU temp was around 75C?.. iStat doesn't show me the chipset temperature, but the heatsink temp seems to be higher now when I have the sound board connected.

Now the fan has been running constantly at 3500-4000rpm just typing this message, no flash banners on any page, no music playing, same room temp. I'd like to have a wireless sound card anyway but haven't found any suitable yet.

[Beliyaal]

Please have a look at this thread and report your results:
http://forums.macrumors.com/showthread.php?t=459306

[Tensakun]

I've used mine on my lap and it's hands down the coolest running laptop I've ever owned. The Air does put the "lap" back in laptop. Proc. temps. avg. in the 40ºs C so the case is a bit cooler. Used for up to 3 hours w. thin pants in lap without noticeably uncomfortable heat.

Thanks NC, good to know. Am looking forward to taking the MBA plunge!

[droppedd]

OK - it seems for me to be pegged almost entirely to using an external monitor, which I do every day for work. I can do most things ok using the built-in LCD, but if I plug in to any resolution external monitor with DVI and just play an album in iTunes with Large visualization on - no other significant programs running, no time machine on, etc. - I get a core drop before I finish a 45 minute album and the visualization starts to stutter.

Being that the computer has 3 ports, i'm a little annoyed that using one of those ports kills half my CPU... But at least now I have it pretty well proven, at least to myself. Back to the apple store in the morning for me; I'll present the Geniuses with my findings and swap this frustrating sucker for another and see what I can find. If anyone can try the same thing (plug into a DVI monitor, turn on Large visualization and play a 30-60 minute album) and report back on their results, that'd be very interesting to see.

[droppedd]

Brought my MBA into the store, plugged it into an external monitor there and replicated the core dropping within 20 minutes for the genius. And he said - and I quote, "that isn't a failing, it's a feature."

Then i asked for a manager and swapped my MBA for a macbook standard.

The computer being single-core performant when I use it for anything intensive for more than 20 minutes on an external monitor is a "feature" I'd rather not have, and the MacBook has no such "feature" - it works with both cores, all the time, unless you do something really weird and outside normal operating parameters.

Shutting down a core is a feature if it happens when you misuse the computer -- eg using it in 120 degree weather in direct sunlight, or when you're blocking the exhaust port -- but under normal usage scenarios (watching a movie and playing some songs in itunes in clamshell mode for 30 minutes) I expect dual-core performance, as advertised. Thanks.

Guess I'll wait for MBA rev2.

[NC MacGuy]

Brought my MBA into the store, plugged it into an external monitor there and replicated the core dropping within 20 minutes for the genius. And he said - and I quote, "that isn't a failing, it's a feature."

Then i asked for a manager and swapped my MBA for a macbook standard.

The computer being single-core performant when I use it for anything intensive for more than 20 minutes on an external monitor is a "feature" I'd rather not have, and the MacBook has no such "feature" - it works with both cores, all the time, unless you do something really weird and outside normal operating parameters.

Shutting down a core is a feature if it happens when you misuse the computer -- eg using it in 120 degree weather in direct sunlight, or when you're blocking the exhaust port -- but under normal usage scenarios (watching a movie and playing some songs in itunes in clamshell mode for 30 minutes) I expect dual-core performance, as advertised. Thanks.

Guess I'll wait for MBA rev2.

Did you try same test with any of their display systems? I find it appalling they would explain it away like that but then again, I haven't been impressed w. many of the Apple employees I've spoken to either.

Hope your MB works great!

[hotdamn]

"that isn't a failing, it's a feature."

Reading that got my blood pressure up. I am really sorry man, hope everything is better with your macbook - it's a great machine too! :)

[droppedd]

Reading that got my blood pressure up. I am really sorry man, hope everything is better with your macbook - it's a great machine too! :)

I'm really liking my macbook standard, it just feels like a brick after the Air - it's a full 66% heavier :) LCD isn't as nice, either.

And the technical problems themselves aside, in general the service I've gotten has been solid. I didn't have to raise too big of a stink for them to exchange my (technically out of return period) Air for a brand new macbook plus a bunch of store credit (since i had bought my original one online). So I'm still satisified with my overall Apple experience, especially when compared with what i've had with any of a half dozen PC manufacturers' support lines, RMA processes, etc.

If you're having similar issues, just be firm about wanting an exchange or return when you bring your computer in and not letting them stonewall you on it being "proper MBA behavior."

[hotdamn]

oh I already got my return acknowledge, I just told them I was sick and tired of dealing with the troubles. They were cool about it, just as you are used from Apple.
Apart from the thinness and lightness, the thing I'll miss the most is this gorgeous keyboard, so much nicer than the one on the pro.

[digitalfx]

on my first vacation w/ mba and it is a joy. watched a 2 hr movie full screen (itunes download) and no heat issues at all...movie never skipped a beat once.
having the mba on a plane makes it worth every cent.

btw to address earlier post about heat. i've owned 6 laptops over the past 5 years and this is by far the quietest and COOLEST I have ever owned...period.

[Coolguy138]

Hello,
Sorry for the really long post but i really want to get to the bottom of this as i really like my air!!
I have been following the over heating topics very closely. I still decided to give the macbook air a shot. Tonight was my first night with the air. I cant get the core to shut down on youtube or imovie (even had several apps going). This maybe because I have not been using it long enough. I down loaded a shareware card game from the apple site called "Solitaire Epic". Since I have been following this problem I have had activity monitor open the whole time. Without fell the sec core will shut down ( might take longer if the air is cold). I did not even notice a lag as the game takes almost no CPU. I looked over and saw that the sec core stopped fluctuating. I tested the dock just to make sure. Sure enough the core was shut down and the dock wasn't as fluid as normal. Here is the weird part the sec i close the game the core turns back on regardless of the temperature readings!! I even tried with youtube open playing a video ( excellerates the shut down while playing the game?). As i played i monitored the temperatures the CPU didn't go too high 70 max. The temp would dip back down to like 69, the youtube video would stutter as the core shut down, fans were at max ( in a well ventilated space on a desk). The moment I closed the solitaire epic ( I mean instantaneous) the core would turn back on and the youtube video would begin to play normally regardless of temperature!!!!.. This however did not work in the opposite manner if i shut down only youtube the core remained shut down untill i closed the solitaire epic game. Not computer savvy just a researcher so i am good with the experimenting but have no idea about these results. So this lead me dow another path. I also own an imac G5 rev c with the camera, anyways i had open photo booth open to the comic effect and left to go eat when i came back my GPU temp was 95 C i have never seen it passed 45 c. So i did another test after the core shuts down with the solitare game I close it and the core started back up i then right away opened photo booth and put it on the comic effect less the 30 sec the core shut down again. Once again the moment I deselected the comic effect or closed photo both the core would start back up again. I do not know if this is a deal breaker for me as I don't know what apps will cause her to shut her core down ( hope i can video chat ). This is my third mac and it steals the sweetness from me I hope this helps, try downloading the game and trying it out. Once again this was in a well ventilated area with the vents unblocked. Hopefully this can be fixed in a software update? Do y'all feel that this problem could cause hardware to fell sooner then it should? I guess the GPU was meant to only bursts of processing? BTW the air was plugged in the whole time!

[ozthegweat]

I have the core shutdown too, but only when watching videos, which then start to stutter.

What happens is: one core shuts down, and the process "kernel_task" shoots up (from ~5% when both cores are active) to 60-70% CPU usage.

This is the reason why the videos become jerky, there's simply not enough CPU power left.

But why does the kernel_task get so high? And does this happen with you, too?

EDIT: Weird thing is: when I stop the video, it takes only about 1 second and the second core is active again. This can't be the temperature, it would go down so quickly.

[Coolguy138]

No i dont have that problem with the kernel task. I can be doing alot of CPU stuff like watching HD videos in itunes and be watching a youtube videos all at the same time. I have yet to see the core shut down while doing that (even when its on my lap). The core only shuts down when its a GPU issue like Photo Booth effect or something like that. Should i try to get a replacement. I have only had it a day and it came preinstalled with 10.5.2. so its a newer one i think. I am just wondering if they all have a core shut down problem just not many people have used the GPU non-stop for awhile which will cause this problem. Try that card game I talk about and see as it takes no CPU but still the fan rev high and if you play a couple of games and see if it starts to lock up. I does happen quicker if the Air is already really warmed up.

[ozthegweat]

Oops, I forgot to add that the core shutdown only happens when watching video on an external display. It doesn't matter, if the internal screen is active or not or if the lid is closed or not.

[Beliyaal]

The most probably thing is that the core shutdowns isn't core shutdowns, because the Intel processors has no such feature. More likely it's only a buggy Intel graphics driver that is causing this issue.

All thermal throttling on the processor is achived by lowering clockspeed or pausing processing for short periods, no core shut down is possible.

[buccsmf1]

had first overheating problem the other day. was simply typing on word and the thing heated up to around 170-180 F within minutes and wouldn't cool off. Vents weren't blocked, it was simply sitting on a desk. And the worst part was that it killed the battery when it was overheating, i had a full charge and it gave me a life of about an hour and a half. I kept it on for about 45 minutes (was taking notes in class and couldnt turn it off) and shut her down. Booted it back up later on in the day and it's worked fine ever since. Not really sure what happened but it does kinda scare me that its gonna keep doing this and eventually do damage to itself.

[droppedd]

FWIW, here are some example screenshots of core drops from when i still had my Air.
Identical setup on my regular macbook now; haven't had this happen even once.