Fixed my kernel_task/sluggish performance/overheating problems in 10.5.7
Hi guys,
so I've been a long time reader of the discussion boards and now I finally have something to contribute. I've bought a Macbook Air (1.8 GHz version) shortly after it was released (Rev. A), over a year ago. As most of you I was bugged with all the now well known problems, flash video stuttering, core shutdowns and the whole thing. Downloaded SMC fan control and bought coolbook and it basically was a useable laptop after that ... until the 10.5.7 update.
I started getting the kernel_task problem as a lot of you have. Basically under heavy load this process ate up all of the processing resources (150 CPU usage for the task, 80-90% system usage of the CPU) which results in sluggish system performance, you cannot even move the mouse smoothly anymore. The air became unusable even under light load. I tried a lot of things to fix it and to be honest it was ultra frustrating, I couldn't even skype and watch a movie simultaniously anymore (not even in quicktime, let alone flash).
So I read some post (I think it was on this board) of someone stating that you should uninstall things like coolbook and similar applications before applying the update, which of course I didn't do ... (thanks man, whereever you are)
So I uninstalled coolbook (go to preferences in the coolbook controller and hit the uninstall button), which essentially removes it's kernel extensions from OS (reboot necessary). I then redownloaded it, just to be sure and installed it again (you'll have to reboot again) and it was fine after that! I seriously couldn't believe it. One thing important to mention though: it came with the default configuration (800 MHz at 0.9 V for both adapter and battery, throttling medium and *temp limit off (!)*). You also can just activate it with your credentials, you do not have to buy it again or anything.
So I did a little stress test, I only configured the 1.8 GHz setting at 1V (lowest I can go without a kernel panic), so the CPU doesn't switch speeds and this produces the most heat, put fans in SMC fan control to max, fired up World of Warcraft, parked my char in the middle of a crowded place (4fps, ouch) had skype running and watched a youtube flash movie in safari. No kernel_task, still perfect performance, nothing sluggish, just perfect, even the flash video was smooth, but boy the CPU got hot. I tested this for about 8-10 minutes, after that the CPU was at 90°C (and still rising!) and I stopped the load so I don't fry my CPU. Do NOT do this, you could damage your hardware. But basically it showed that the kernel_task didn't kick in as it usually would at about 65°C ...
So my conclusion is, that the kernel_task, as many of you have suggested already, is heat related, trying to throttle down the CPU to protect it from damage. I suspect that the coolbook kernel extension somehow was messed up with the latest update to 10.5.7 or they somehow clashed with each other. Truth is, I don't know and probably won't find out, but it's a decent hypothesis at least.
The important thing is, it works again. So to sum it up:
- I uninstalled coolbook, effectively removing it's kernel extensions and restarted
- reinstalled coolbook and restarted
Currently I've set coolbook to remain at one processor speed (1.2 GHz @ 0.9V, so it doesn't heat up too hard), but I think it's all good now and I'll set it up again tomorrow with the rest of the settings. I've used my air the whole evening and I didn't have any problems since and did all the stuff I couldn't do 2 days ago.
Well I hope that reinstalling coolbook helps a lot of you guys. I can't tell you how relieved I am that my air works fine again and now I hope that it'll help you too!
Cheers,
roofkid
so I've been a long time reader of the discussion boards and now I finally have something to contribute. I've bought a Macbook Air (1.8 GHz version) shortly after it was released (Rev. A), over a year ago. As most of you I was bugged with all the now well known problems, flash video stuttering, core shutdowns and the whole thing. Downloaded SMC fan control and bought coolbook and it basically was a useable laptop after that ... until the 10.5.7 update.
I started getting the kernel_task problem as a lot of you have. Basically under heavy load this process ate up all of the processing resources (150 CPU usage for the task, 80-90% system usage of the CPU) which results in sluggish system performance, you cannot even move the mouse smoothly anymore. The air became unusable even under light load. I tried a lot of things to fix it and to be honest it was ultra frustrating, I couldn't even skype and watch a movie simultaniously anymore (not even in quicktime, let alone flash).
So I read some post (I think it was on this board) of someone stating that you should uninstall things like coolbook and similar applications before applying the update, which of course I didn't do ... (thanks man, whereever you are)
So I uninstalled coolbook (go to preferences in the coolbook controller and hit the uninstall button), which essentially removes it's kernel extensions from OS (reboot necessary). I then redownloaded it, just to be sure and installed it again (you'll have to reboot again) and it was fine after that! I seriously couldn't believe it. One thing important to mention though: it came with the default configuration (800 MHz at 0.9 V for both adapter and battery, throttling medium and *temp limit off (!)*). You also can just activate it with your credentials, you do not have to buy it again or anything.
So I did a little stress test, I only configured the 1.8 GHz setting at 1V (lowest I can go without a kernel panic), so the CPU doesn't switch speeds and this produces the most heat, put fans in SMC fan control to max, fired up World of Warcraft, parked my char in the middle of a crowded place (4fps, ouch) had skype running and watched a youtube flash movie in safari. No kernel_task, still perfect performance, nothing sluggish, just perfect, even the flash video was smooth, but boy the CPU got hot. I tested this for about 8-10 minutes, after that the CPU was at 90°C (and still rising!) and I stopped the load so I don't fry my CPU. Do NOT do this, you could damage your hardware. But basically it showed that the kernel_task didn't kick in as it usually would at about 65°C ...
So my conclusion is, that the kernel_task, as many of you have suggested already, is heat related, trying to throttle down the CPU to protect it from damage. I suspect that the coolbook kernel extension somehow was messed up with the latest update to 10.5.7 or they somehow clashed with each other. Truth is, I don't know and probably won't find out, but it's a decent hypothesis at least.
The important thing is, it works again. So to sum it up:
- I uninstalled coolbook, effectively removing it's kernel extensions and restarted
- reinstalled coolbook and restarted
Currently I've set coolbook to remain at one processor speed (1.2 GHz @ 0.9V, so it doesn't heat up too hard), but I think it's all good now and I'll set it up again tomorrow with the rest of the settings. I've used my air the whole evening and I didn't have any problems since and did all the stuff I couldn't do 2 days ago.
Well I hope that reinstalling coolbook helps a lot of you guys. I can't tell you how relieved I am that my air works fine again and now I hope that it'll help you too!
Cheers,
roofkid
Macbook Air, Mac OS X (10.5.7), 1.8 Ghz, 80 Gb