My 15″ MacBook Pro gets very very hot. So hot that it’s actually uncomfortable to have it sat on your lap. So I was very happy to find out about smcFanControl, which allows you to manually set the fan speed of your MacBook or MacBook Pro.

smc Fan Control
I found that smcFanControl reported a temperature of over 60 degrees celsius for my 15″ MacBook Pro, which is really quite scary (and explains why my legs were getting so very hot). By setting speed of the two fans to be 4,000 rpm rather than the minimum of 1,000 rpm, the reported temperature dropped to 40 degrees within a minute or so. This is nothing more than lukewarm to the touch, and is much more comfortable.

I can’t be 100% sure what this all means for your warranty, although smcFanControl isn’t doing anything more than your Mac does when it thinks it’s too hot. Also, usefully, smcFanControl won’t let you set the fan speed below the minimum allowed by Apple. But for me, it’s made a huge difference to using my MBP on my lap. Many thanks to Hendrik Holtmann for making this excellent bit of software available for free.

Now, if only Apple could make the things cooler in the first place…