First a little background: I've got lots of computers, including Linux PCs and two MacBook Pro (and a MacMini). My concern is with my 'old' MacBookPro (Core Duo). It really does overheat. Warranty is long void. Years ago (I'd say 2.5 years ago or so) one day it overheated so bad that the battery inflated due to the heat. I got a new battery for free but it's still getting incredibly hot (much other than any other computer I've got: my newer Core 2 Duo MacBook Pro doesn't get nearly as hot as the old one. It s really a pain because I use my old MBP when I m in front of TV, having it on my lap, and it can really become unbearable.

I don't want to open that old MBP.

On Linux I can force a new CPU 'governor' that decides how the CPU is allowed to operate: it can be 'on demand', 'always max speed', 'always speed x', etc.

Does the same exist under MacOS X?

Is there a way, say if a 1.86 Ghz Core Duo can run at 1.6 Ghz, to ask MacOS X: "never run this CPU above 1.6 Ghz" ?

2 Answers 2


I've used SMC Fan Control to kick up the fan speed on my old MacBook. Also, depending on your processor model, there may be a setting in the Energy Saver panel of System Preferences that will allow you to set the CPU speed.

  • @John Douthat: damn I don t see anything like that in the Energy Saver panel. In addition to that I d rather have it quiet, which is why I d prefer to lower the CPU speed than rev the fan up :-/ Feb 27, 2010 at 1:46
  • I keep seeing SMC Fan Control everywhere, but it's pretty limited. I like Macs Fan Control way more. With the latter, I can monitor the GPU temp, and set the fans to come on earlier, depending on the temp - which is the whole idea. Setting the fans a little higher 24 hours a day, which is all you can do with SMC Fan Control, makes zero sense to me. Sep 25, 2016 at 12:32

You could try undervolting the cpu with coolbook, which comes at a price of $10. Here's a link to a forum where it is discussed + some more links.

It looks like this, according to their website.

alt text

This may void the warranty, but luckily yours has expired!

  • 1
    @trolle3000: +1, Interesting, this may be what I was after. I don't like the fact that it's not free nor potentially warranty voiding (meaning it may break havoc) but basically it looks like what I was after :) Feb 27, 2010 at 8:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.