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MacBook Air Mid-2009 overheating in Lion.

Hello!

I own a MacBook Air Mid-2009 (2,1) and it overheats really badly. In Lion it is even WORSE 😟

I'm just browsing the web, no Flash, etc, and it gets VERY hot. This, in ~10 mins after i wake it up. Of course, kernel_task eats up the entire CPU then (140%) and it becomes unusable. The mouse barely moves.

The Air is a pretty powerfull machine (1.86 C2D, 2 Gigs of ram) but the cooling isn't enough. OR OS X takes actions too fast (at ~70 degrees celsius). I ran a simple test. I always hated Windows, but now it impressed me. On OS X, i started a 3D java game, in ~30 secs, kernel_task is killing the CPU, the game plays at 5-6 FPS.

Booted Windows 7, started the same game. Played for 2-3 hours (multiplayer FTW 😀) and i noticed that Windows allows it to overheat more (the case felt much more hotter than in OS X) BUT the game worked nicely, at ~100 FPS. Continously.

So, OS X kills the CPU too fast. Maybe there is a tweak for it to allow more overheating. In Snow Leopard, it overheated slower, but the same problem. I tried CoolBook to undervolt, which apparently modifies Apple's driver for the CPU. And also disables this protection, with kernel_task. It worked nicely, but i want to have Apple software, not 3rd party. And also, it should work out-of-the-box, without additional software.

I always use it on a metal-desk.

So, i can't use it for basic stuff. Such as Twitter, Safari, Xcode, etc.

What do you think?

MacBook Air Mid 2009, Mac OS X (10.7)

Posted on Jul 22, 2011 6:53 AM

19 replies

shojo123

Level 1

0 points

Aug 23, 2011 3:36 PM in response to Kurtz25

Did yoi go back to 10.5 ?

ATab

Level 1

0 points

May 13, 2012 12:16 PM in response to andreigherghe

I did two things that seem to have helped.

1. DropBox: Big CPU consumer and lots of HDD spinning. Some of it for the right reasons, but there were some troublesome files that it had trouble with and kept trying to sync.

2. http://reviews.cnet.com/8301-13727_7-20023166-263.html shows you how to remove Spotlight related plugins. MS Office-related one tends to be the biggest culprit.

Hope this helps some of you.

Aug 24, 2012 6:07 AM in response to andreigherghe

Are people still having these issues? (It's august now for the love) I'm still running Snow Leopard on my early-2010 mb air because Lion was so slow I downgraded. I'm tempted to upgrade again but I don't want to waste my time if it's going to be slow as molasses...still.

LormaD

Level 1

0 points

Mar 23, 2013 12:29 PM in response to andreigherghe

I have a late 2010 Macbook Air w/ 2.13 Core 2 Duo , 4GB DDR3, and 256SSD that came from the factory... and the heat and fan noise generated whenever using my mac to watch any kind of online streaming (youtube, videos, or playing mpeg4 Videos) would have the fans kick in to 6500rpm within a minute or so (iStat was registering the CPU temperature at above 90C, where it would be idling at 65-68C when not watching any kind of videos).

I eventually caved in, and decided to order the necessary screw drivers / bits to open up my macbook air and have a look inside. Was reading alot about how poorly the cpu's thermal grease was applied, and how others were reporting success. I tried the pram and smc resetting, but noticed no difference before or after.

Before redoing the thermal grease on my CPU / GPU my Temperatures reporting with iStat showed the following...

(no web browsing i.e. no emails, nor reading online...): Idle Temp 52C

(Web, reading emails, online, but no flash or streaming): Browsing Temp 68C

(Watching online streaming or playing MPEG Videos): Streaming Temp 92 - 95C

After applying thermal grease on CPU and GPU: 38*C / 46*C / 72**C (streaming within a window sized screen) 82***C (Streaming Full Screen).

Respecting Fan Speed:

* = 2000rpm steady

** = 3000 - 3250 rpm mildly varying below 3000rpm (can't hear it)

*** = 3800 - 4200 rpm variable (need to listen for it to notice it, but late at night with earphones on, I do not disturb the person sleeping next to me).

Before, I could not stream any kind of video without the fans kicking in and whurring away at 6500rpm.

I was planning on replacing my macbook late 2010 air, but after this very successful mod, I love it all over again (more than my 15" macbook pro retina).

Cheers,

LormaD

MacBook Air Mid-2009 overheating in Lion.