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zachsandberg

macrumors newbie
Original poster
Aug 29, 2011
3
0
Like a few of the more engineering minded types on this board I've noticed that my 2.5GHz i5 Mac Mini runs at some very high temperatures (90-96c) when pushed to the max, and while I've been reassured by a few people that this is normal and within the "Apple specs", this thermal limit has me concerned or at the very least, curious.

I'd like to see what other people are getting for upper limit temps with their Minis as it may help to establish consistency and improvement baselines for future firmware releases.

To establish my max temp I opened terminal with 4 tabs (or 8 tabs for Quad Core server models) and ran: "yes > /dev/null" in each of the terminal instances. My fan remained at 1800rpm up until the 90c mark where it then slowly rose to around 5500rpm. The temperature spiked to 96c at it's highest and fluctuated between 89-92 at maximum fan speed. (Room temp was around 24C)

One more related thing I did notice was that the temperature of the GPU increased 10c at idle when hooked up to dual 1920x1080 monitors vs a single one. I suspect this will be common with those of us that sprung for the ATI 6630 graphics chip.

Anyway, just curious to see what other people are seeing for temps :)

Zach
 
The Intel processors used in Macs are designed to automatically shut down to prevent damage if they truly overheat (around 100C/212F - 105C/221F, depending on your processor). As long as your Mac isn't shutting down, it's not overheating. iStat Pro will give you accurate readings of your temps, among other things.

Unless there is a rare defect in your Mac, your temps are well within the normal operating range, considering the workload you're putting on it. Websites with Flash content, games and other multimedia apps will put higher demand on the CPU/GPU, generating more heat. This is normal. If you're constantly putting high demands on your system, such as gaming or other multimedia tasks, expect temps to rise and fans to spin up accordingly. It's just your Mac doing its job to maintain temps within the normal range.
 
It's just your Mac doing its job to maintain temps within the normal range.

I've already seen this canned response on another thread and I find it to be a bit ridiculous since it offers no response to my inquiry. I know what the published specs are for the thermal limits on my processor, thanks. I'm also sure that Apple designs wonderful computers as well, however I'm only interested in comparing my temps to other peoples' temps here.
 
I've already seen this canned response on another thread and I find it to be a bit ridiculous since it offers no response to my inquiry. I know what the published specs are for the thermal limits on my processor, thanks. I'm also sure that Apple designs wonderful computers as well, however I'm only interested in comparing my temps to other peoples' temps here.
It's not a canned response; it's an accurate response. Comparing your temps to others is meaningless, since everyone has different operating conditions, configurations and environmental factors.
 
I've already seen this canned response on another thread and I find it to be a bit ridiculous since it offers no response to my inquiry. I know what the published specs are for the thermal limits on my processor, thanks. I'm also sure that Apple designs wonderful computers as well, however I'm only interested in comparing my temps to other peoples' temps here.

The previous post did include that, 105C/221F, as it is for all CPUs that Apple uses.
 
The previous post did include that, 105C/221F, as it is for all CPUs that Apple uses.

Actually, it would be 100c for the i5 2520 as GGJstudios said above.

Also, a real world comparison of temperatures is not "meaningless". It's unscientific for sure, I'll give you that. It definitely means something to myself and from what I've seen, to a handful of others as well.
 
My Mini I5 2.5Ghz with four terminal tabs running the described tests(no other apps), showed max cpu temp of 95,96 degrees celsius. Fan speed was at max 3800rpm´s with brought the temps down to 70-75 degrees celsius. This was going on for about 6-8 "bursts" as the cpuload didn´t max out continuously. The mini had been powered on for 10hours before the tests was done. I´m guessing the room ambient temperature was about 20-22 degrees celsius.

/Regards Henrik
 
My i5 2.5 is running around 194f.

Handbraking... fan is screaming at 4228rpm

I have terminal open so I can purge ever so often... I'm more concerned about my RAM issue then a heat issue right now though.
 
It's not a canned response; it's an accurate response. Comparing your temps to others is meaningless, since everyone has different operating conditions, configurations and environmental factors.
Ya... It really isn't worth it to do this. Unless you have some controlled environments, proper testing equipment and a background in statistics this isn't going anywhere. Just leave the engineering to the engineers. If and when your Mac starts to have problems when you run a normal workload on it, instead of a synthetic you created, then take it to Apple for a checkup and needed repairs.

Personally, I run my Mini 24\7 and frequently que up very lengthy video encodes lasting many hours at a time. It has been running with no reboots through many days of this real world application. They are great systems with really well throughout thermals.
 
temperature

my mac mini 15 is runing around 89-95C
Handbraking .. fan is 5580 rpm and 97C...very noisy :eek:
 
i7 handbreaking: 5500rpm and 90-91c. Way too noisy :-(

Hm, have now taken the bottom plate off and raised the machine a little (or the fan would be almost flush with the table). Temps are 84-87 and 33-3500rpm - still noisy, but significantly less so.
 
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Damn, maybe a bit too quick;

Fan is now at 4500rpm with the cpu at 80c. Maybe because the rest of the machine is heating up; memory, gpu, airport and ambient is at 55-60c.
 
To a certain extent, this behavior is by design.

Intel's Turbo Boost will ramp up the CPU clock to higher speeds in order to maximize performance under load. This will make it run hotter, but the Turbo Boost will back down once thermal limits are exceeded.

The temperature behavior you see is probably a combination of the system fan lagging temp a little bit (so initial rise to high temps >90C, but once the fan ramps up the temps are kept around 90C) and Turbo Boost continually pushing your CPU up trying to maximize performance but keeping it just below the max thermal limit.

It would be interesting to see if there was a tool/hack that could disable turbo boost, and see if temps (or performance) were significantly altered with it off.

Ruahrc
 
Bizarre thermal runaway on my 2011 Mac mini -

I booted my Mac mini (see specs below in sig) and began using it. After around 10-15 minutes, it began to seem quite sluggish. I thought maybe it was something weird Safari was doing (since I was on a site with heavy javascript). Quit Safari. Still slow.

Launched Activity Viewer to see what was slowing things down, but nothing was using more than normal amounts of processor time. Now the machine seems even slower. So, I'm thinking, "how odd."

I hit the Restart menu option the machine, and as it's doing the spinny icon thing that it normally does when shutting down, the machine powers off. I reached down to hit the power button on the back and the machine is burning hot!

Unplugged everything, let it cool down, flipped it upside down and took the bottom cover off. I thought maybe the fan stopped working. Plugged in power and one display and hit the power button. It started right up and the fan began running. OK, fan is working. Machine booted normally. Fan speed was on the higher side (by sound) but seemed to be otherwise fine. After a couple hours it's back to normal and hasn't happened since. I've since installed the smc fan utility and temps are perfectly normal now. Just to be safe, I've boosted it to 2300 rpm. Noise isn't noticeable.

Don't know what caused it but it was really weird.
 
Fan speed 1800 rpm

HD Mcintosh 32

CPU 44

Airport card 37

Ambient 36

Ambient 2 37

Memory 41

Memory A1 43
 
How about a cooling fan?

I just ordered a Mac Mini Server (hope I can install Lion Client on it to use with Pro Tool 9 BTW), but if it runs hot wouldn't it be practical to buy a small laptop fan to put underneath it, or am I missing something? If so, does anybody have a suggestion about what is the best fan for this use? Thanks!
 
I am not sure that adding a laptop fan underneath the mini will do much in the way of cooling. The design of the cooling system in the mini is such that not much of the heat would be transmitted to the bottom of the case (unlike laptops).

Putting a fan to blow on the aluminum chassis might help some as it seems to contribute somewhat by radiating heat.
 
Before the 2011 model was released I vented my doubts about heat production.

The 2010 model has a CPU that is approx 18 W and the GPU is approx 13 W.

The 2011 model i5 is 35 W and the i7 is 45 W. The AMD GPU is 10 ~ 15 W.

So you are looking at (18+13) versus (35+10/15) or 45 W heat dissipation.

The PSU will have to deliver more power as well, aiding the heat build up.

Some will have put a second HDD in the i5 / AMD which adds another heat source.

IMHO the cooling system is inadequate for this higher heat production. It is fine for sporadic bursts but not for continual high loads.

I measured the inlet gap and it is approx 1 mm wide and in the order of 20 cm long. Exhaust is 7 cm x 4 mm. If confronted with overheating my first approach would be to give the fan less intake restriction, perhaps drill a few neat holes in the antenna area in the plastic bottom cover and place the computer on some rubber feet. I suspect it will not make a large difference but one will not know until tested.

Anything more will require some drastic redesign of the cooling system and outside the scope of the average user.

One thing I found in Intel's documentation is that it is not advised to run these CPU's above 85 C although the max temprature is 100 C. As such you may want to consider some third party software to kick in the fan at a lower temperature.

I am glad to have bought the mid 2010 model just before the release of the 2011 model and will wait for the release of the 2012 model to see if Intel by that time has gotten their act together on low power consumption CPU's and if Apple has redesigned their cooling system.

PS I have a Thinkpad T61p, in its time it was the Thinkpad flagship and one of the fastest laptops around. The initial production had lots of problems with the GPU failing: the vendor never expected it to be used for gaming. Later in the lifecycle the motherboard was redesigned and the cooling system totally overhauled - if you got one of the later ones it was fine. I got the last one that came of the line :D but when I bought it I was not even aware of the GPU issue. Just shows that it may be wise not to be the first one to buy the latest and greatest (besides a considerable price advantage).
 
Wirelessly posted (Opera/9.80 (iPhone; Opera Mini/6.1.15738/25.858; U; en) Presto/2.5.25 Version/10.54)

I have the 2011 mac mini i5 with the amd hd 6630m i use a 80mm usb fan to blow air onto the unit and play world of warcraft for hours and the mac feels cool to the touch no problems at all with temps.
 
Bright aluminium does not radiate / absorb much heat. The external fan proves that the internal cooling is inadequate.

You may want to add some heatsinks to the sides and attach them with thermal transfer tape (no drilling required).

You'll have to hunt around for the correct lenght of heatsink and may have to cut it to the right height. I've done this in the past using a normal tungsten tipped mitre saw. (make sure to clamp it properly and never just hold it - you may loose your hand)
 

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Bright aluminium does not radiate / absorb much heat. The external fan proves that the internal cooling is inadequate.

You may want to add some heatsinks to the sides and attach them with thermal transfer tape (no drilling required).

You'll have to hunt around for the correct lenght of heatsink and may have to cut it to the right height. I've done this in the past using a normal tungsten tipped mitre saw. (make sure to clamp it properly and never just hold it - you may loose your hand)
ROFL. That's awesome.
 
Bright aluminium does not radiate / absorb much heat. The external fan proves that the internal cooling is inadequate.

You may want to add some heatsinks to the sides and attach them with thermal transfer tape (no drilling required).

You'll have to hunt around for the correct lenght of heatsink and may have to cut it to the right height. I've done this in the past using a normal tungsten tipped mitre saw. (make sure to clamp it properly and never just hold it - you may loose your hand)

Holy crap lol I don't think my Mac mini i5 ever got hot enough to make me want to add heatsinks to the side haha I'm sure the stock cooling is fine and like I said a simple USB fan blowing air at the mini will cool it by 20c under a load but even that is not needed
 
Turn That Frown.......

......Upside Down.

For cooler running Mac Minis, turn them upside down.

Seriously.

I have a 2011 Mini with i7 and the AMD 256MB video card. The only game on it that causes it to heat up and turn the fan on is Eve Online for me because its a Wine Windows port. Fans really rev up whenever I'm docked at a starbase. So first I tried removing the bottom and running the Mini upside down. That caused the fan to speed up. So I put the top back on and it quieted down.

And down.

And down.

The fan still works. I really stressed the machine and got them to rev up, plus Mac Fan Control shows the fan is still varying in speed. It turns out the air intake is on the bottom so by turning it upside down I'm giving the Mini more access to cooler air. I love having a silent machine again.

Let me know your results.
 
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Respectfully, I do not think is the more access to cooler air. I think what happens is that if the Mac mini is in it's "normal" postion the hot air rises up inside the enclosure and cannot escape easily whereas if it is upside down the air is against the plastic cover and gets sucked out by the fan inlet. In other words: in the "normal" position the fan inlet is closest to the "floor" where the coldest air resides and is furthest away from the "hottest" air, flipping the machine upside down reverses this.

Thank you for reporting this worthwhile observation.
 
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