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Cynicalone
Jul 24, 2011, 01:13 PM
I posted these in another thread but I thought I would gather them in one place.

I was curious to see how the Air would handle an encode. So I plugged in the MacBook Air Superdrive and fired up the 64-bit version of HandBrake. I used a DVD of the movie Seven. I choose the default iPad encode settings, and took some screen shots along the way.

At the beginning...

295722

A few minutes in...

295723

About 20 minutes later...

295724

And at the very end of the encode...

295725

The Air was stable and useable the whole time it took to encode the movie. I continued to use Safari and other apps while the Air worked away. I was very impressed with the performance of the i7.



theSeb
Jul 24, 2011, 02:19 PM
Pretty much what I get.

http://forums.macrumors.com/showthread.php?t=1193767

I am going to try again to see if things remain the same.

rkahl
Jul 24, 2011, 02:36 PM
Is that normal for CPU's?

Baycity
Jul 24, 2011, 02:37 PM
I know! I ****ing love this thing! I was previously using my macbook from 4 years ago and wasn't able to do a good 1080p transcode to save my life (under 3 days).. so i was considering a macbook pro but wanted to wait for the next model. I got this new macbook air last night and converted a 1080p full length movie in around 4 hours while importing my iTunes library. This thing is really a beast!

Cynicalone
Jul 24, 2011, 02:51 PM
Is that normal for CPU's?

The full 100% usage? It's normal for Handbrake it's well coded to use all the power you can give it.

rkahl
Jul 24, 2011, 04:35 PM
The full 100% usage? It's normal for Handbrake it's well coded to use all the power you can give it.

The Heat.

theSeb
Jul 24, 2011, 04:55 PM
The Heat.

Yes. It's rated by intel to handle up to 100 degrees Celsius

Cynicalone
Jul 24, 2011, 05:03 PM
The Heat.

The temps won't hurt anything it is below the max that Intel says is the limit.

engrwpride
Jul 24, 2011, 05:20 PM
What is the normal tolerance for temperatures like this? Do laptops generally run only a few degrees below the limit?

Dave421
Jul 24, 2011, 05:39 PM
Awesome. Thank you for posting this. I've been looking for something that I could compare to my 2011 mbp to determine whether to go for the new mba and this is exactly what I was looking for. So nice to see that it's pulling in 60fps.

mulo
Jul 24, 2011, 05:42 PM
I got this new macbook air last night and converted a 1080p full length movie in around 4 hours while importing my iTunes library. This thing is really a beast!

for comparison, my 2011 17" MBP will do a 2 hour 1080p movie encode in ~45 mins ;)

theSeb
Jul 24, 2011, 05:45 PM
Awesome. Thank you for posting this. I've been looking for something that I could compare to my 2011 mbp to determine whether to go for the new mba and this is exactly what I was looking for. So nice to see that it's pulling in 60fps.

It depends on what you're encoding.

Obscurelight
Jul 24, 2011, 05:49 PM
interesting, thanks for the info

Arni99
Jul 25, 2011, 05:04 AM
Handbrake encoding benchmark of the MBA 2011 vs. MBP etc.:
http://barefeats.com/mba11_02.html

jackyyeow
Jul 25, 2011, 05:25 AM
for comparison, my 2011 17" MBP will do a 2 hour 1080p movie encode in ~45 mins ;)

Amazing, can't imagine what kind of speed you'll get in the coming Ivy Bridge.:eek:

riggers
Jul 25, 2011, 06:50 AM
Handbrake encoding benchmark of the MBA 2011 vs. MBP etc.:
http://barefeats.com/mba11_02.html

Would be interesting to see what speed improvement an SSD would give to the MBP's...

lukekarts
Jul 25, 2011, 06:52 AM
Those results are quite scary. 207 deg. F is roughly 97 degrees C - only 8 degrees before the automatic shutdown point for the Core i7. I dread to think what it would be like on a hotter day once a little bit of dust builds up inside. On the plus side you can boil some water and make a cup of tea.

TheEmpty
Jul 25, 2011, 07:08 AM
Is handbrake better then AnyVideo Converter? I've used that on my PC a lot and really like it.

Roman2K~
Jul 25, 2011, 07:21 AM
Those results are quite scary. 207 deg. F is roughly 97 degrees C - only 8 degrees before the automatic shutdown point for the Core i7. I dread to think what it would be like on a hotter day once a little bit of dust builds up inside. On the plus side you can boil some water and make a cup of tea.

Regardless of ambient temps, these Sandy Bridge CPUs do not let themselves heat up past their "junction temperature (Tj)" (100C) or a little less.

So when you see 97C as in the OP, there's a good chance the CPU is already throttling itself (starting with clock speed, then shutting down cores) to keep under 100C.

lukekarts
Jul 25, 2011, 08:23 AM
Regardless of ambient temps, these Sandy Bridge CPUs do not let themselves heat up past their "junction temperature (Tj)" (100C) or a little less.

So when you see 97C as in the OP, there's a good chance the CPU is already throttling itself (starting with clock speed, then shutting down cores) to keep under 100C.

That makes sense, but it effectively means that performance will be compromised; which presumably will degrade over time (due to dust build up etc.). Not trying to be deliberately negative, but I'm contemplating buying one but the temperatures do look a lot higher than I've experienced in recent years.

Roman2K~
Jul 25, 2011, 08:48 AM
That makes sense, but it effectively means that performance will be compromised; which presumably will degrade over time (due to dust build up etc.).

Exactly... Unless core temperatures are below 95C, one can be almost certain they're not getting the most computing power out of their CPU. It looks like Sandy Bridge processors are hitting the limits of current thermal designs in MBPs and MBAs.

Not trying to be deliberately negative, but I'm contemplating buying one but the temperatures do look a lot higher than I've experienced in recent years.
I had the same problem with a 2011 15" MBP (quad-core i7 2.2 GHz). Before replacing the thermal paste: 97C+ / after : 93C max (in HandBrake). This difference doesn't look like much, but it meant full processing power and generally a lot quieter experience.

So until either Apple redesign their cases, internally at least, or Intel release cooler running CPUs, or both, we're stuck with throttled CPUs (when pushed to the max).

KPOM
Jul 25, 2011, 09:00 AM
Regardless of ambient temps, these Sandy Bridge CPUs do not let themselves heat up past their "junction temperature (Tj)" (100C) or a little less.

So when you see 97C as in the OP, there's a good chance the CPU is already throttling itself (starting with clock speed, then shutting down cores) to keep under 100C.

True. I used Handbrake on Saturday to encode a DVD, and I noticed that at one point it shut down one of the virtual cores (i.e. stopped hyperthreading) as the CPU temperatures hovered around the 205 degree mark (Fahrenheit). The bottom of the Air certainly got hot, though the base temperature reading was usually around 95 degrees. FWIW, it was 100 degrees outside in NYC this weekend.

Exactly... Unless core temperatures are below 95C, one can be almost certain they're not getting the most computing power out of their CPU. It looks like Sandy Bridge processors are hitting the limits of current thermal designs in MBPs and MBAs.

Do those notebook coolers do anything? I wouldn't use one all the time, but if it would help when doing encoding it might be worth the $20.

theSeb
Jul 25, 2011, 09:08 AM
A quick update on this: Initially I was getting around 94 to 96 degrees Celsius. I am encoding again right now and I can't go past 89 degrees Celsius. In fact it's running at 76 degrees Celsius.

CPU Usage for user is about 92-94, as previously. Fans are at 6496. Heatsink is 42.

Here is my previous screenshot.

http://i52.photobucket.com/albums/g35/da_seb/ScreenShot2011-07-22at010135.png

Roman2K~
Jul 25, 2011, 09:33 AM
Do those notebook coolers do anything? I wouldn't use one all the time, but if it would help when doing encoding it might be worth the $20.

I seriously doubt notebook coolers can have any effect on MacBooks as they have no air intake vents at the bottom.

A quick update on this: Initially I was getting around 94 to 96 degrees Celsius. I am encoding again right now and I can't go past 89 degrees Celsius. In fact it's running at 76 degrees Celsius.

It's possible that the thermal paste is in the process of settling. This phenomenon happened to 2011 MBPs (as seen in the related threads on MacRumors forums): temperatures have decreased by themselves within the first few days as thermal paste settled progressively.

theSeb
Jul 25, 2011, 09:36 AM
I seriously doubt notebook coolers can have any effect on MacBooks as they have no air intake vents at the bottom.



It's possible that the thermal paste is in the process of settling. This phenomenon happened to 2011 MBPs (as seen in the related threads on MacRumors forums): temperatures have decreased by themselves within the first few days as thermal paste settled progressively.

I suspect that you may be right.

Cynicalone
Jul 25, 2011, 10:13 AM
Regardless of ambient temps, these Sandy Bridge CPUs do not let themselves heat up past their "junction temperature (Tj)" (100C) or a little less.

So when you see 97C as in the OP, there's a good chance the CPU is already throttling itself (starting with clock speed, then shutting down cores) to keep under 100C.

I was doing the test in my office at the house which I keep at 70 fahrenheit.

If the Air was throttling it was minimal, because I continued using it during the encode and watched the CPU's and temps the whole time to see what it would do.

I had all my regular apps open and it never showed any signs of trouble.

The encode took a while but it was a steady 55 to 60 fps, nothing in comparison to doing it on my Mac Pro but certainly not bad for a MacBook Air.

If I wanted to test again after the thermal paste has settled out how long should I wait?