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]

GPU not CPU?

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)?