Laptop Cooling Hack

by Erica Sadun

MacRumors poster Rockem modified some .kext files to change when his laptop's fans should kick in.


I just modified some .kext files to tell when my mbp to kick in the fans and to run them a bit faster. Now my processor is 40˚f-50˚f cooler, and 5˚c-10˚c for all you out of the usa. Battery life is maybe 5min shorter, and the fans are not all that much louder. 50% cpu with modifications is the same as my idle temps before and 100% cpu with mods is like 50%cpu without mods.

Instructions (PDF Download)

10 Comments


2006-10-08 16:38:24
Um, no warning about modifying .kext files, with description that equates a change of 40-50°F with 5-10°C? (a change of 40-50°F is roughly a change of 22-28°C) Maybe this works as described, but why should I trust this?
Erica Sadun
2006-10-08 17:01:30
Trust nothing.


On the other hand, all you're doing is modifying what's essentially a text property list,e.g. PollingFrequencyInSeconds, MaxTempDeltaBeforeDecrease and so forth. The hack makes suggestions about adjusting your settings, but you're the one who chooses what those settings are.

Andy Lee
2006-10-08 18:34:08
Your Editorial Judgment May Vary, but I agree with Anonymous that there should have been a caveat about mucking with system settings. Fortunately, there are warnings in the PDF file, but I think it would have been worth putting one here too.


On the other hand, all you're doing is modifying what's essentially a text property list


This reasoning actually scares me more than the lack of a caveat. It implies that modifying property lists is an inherently trustworthy operation. Do you know for a fact that this is true?


Hey, all you're doing with "rm -rf /" is typing a few characters into a window. I type characters into windows all the time with no ill effects!


I'd have been a lot less nervous if you'd stopped at "Trust nothing."


That said, I have an old slightly broken G4 iMac that I can afford to use as a guinea pig. If I can stop it from sounding like a jet engine, without overheating and setting my apartment on fire, it might have a new life as a useful machine in my home setup.

Erica Sadun
2006-10-08 19:39:47
Yes, it's a lot less worrisome in my opinion to edit a text-based property list where the names of the properties are right out there in the open versus doing something like bit-editing on a binary where it is far less clear what you are doing. If you want to see my complete opinion about this matter and about modding your mac, feel free to consult Modding Mac OS X.


As I did not include directions in my post, I thought it was overkill to include legal, ethical, moral and technical disclaimers. Such (or at least a subset of such) appear in the material I linked to.

Rocco
2006-10-09 15:12:46
may I know your MBP week production ?
Mine is W8609, wich it means week 9
I've tried the hack but for me it doesn't change anything.


My MBP configuration is:
1,83 ghz, 80 Gb HD, 1 GB Ram (2x512)


Do you have any suggestions ?


what is the maean of each entry in .plist files ?


thanks.

Tim Stephens
2006-10-10 14:20:20
A 40-50F change is not a 5-10C change. I guess that you typed 40 and 50F into the convertor widget and used that value (an air temperature of 5C is about 40F). As anonymous says, it's a 22-28C change.
Erica Sadun
2006-10-10 14:39:26
Tim, it's a direct quote from the original author. I posted and linked including the glaring math error.
rocco
2006-10-11 03:28:40
"may I know your MBP week production ?
Mine is W8609, wich it means week 9
I've tried the hack but for me it doesn't change anything.


My MBP configuration is:
1,83 ghz, 80 Gb HD, 1 GB Ram (2x512)


Do you have any suggestions ?


what is the maean of each entry in .plist files ?


thanks."


Any suggestion ?


Thanks

Tom Chandler
2007-01-02 03:15:51
well you know its all well and good but realy, what is the point.

2007-02-22 16:31:21
when i click on appleblower it says what application would you like to open it in ? and i dont know???????