Why does Firefox make my MacBook's CPU run so hot?

2 replies [Last post]
Joined: Dec 19 2003
Posts: 14

I have a Late 2007 MacBook 2.2 Ghz. Still a great machine, especially for its age. One thing I've noticed recently is that when I'm running Firefox, even if I just have Firefox and nothing else open, the fan will rev up to max speed and the CPU's temperature will go through the roof - I've even seen it hit 100 degrees celsius a couple of times. This is just with Gmail, Facebook, and a forum open. In comparison, if I use Safari the CPU sits on around 55 or so degrees, and the fan hums along at 1800 rpm.

I've tried clearing everything from my history, just wondering if anyone has any other ideas? Or if this is something that Firefox just does.

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Joined: Apr 24 2012
Posts: 255
Re: Why does Firefox make my MacBook's CPU run so hot?

The only thing that comes to mind is the Flash issue, Macs have problems with video in flash format. Try removing the flash plugin.
Hope it helps

volvo242gt's picture
Joined: Nov 9 2004
Posts: 25
Re: Why does Firefox make my MacBook's CPU run so hot?


Does it seem to be more with Facebook than anything else? Do you have AdBlock Plus installed? If so, add this to your filters: facebook.com##span.uiSideNavSpinner

Click Custom Filters in the Filter Preferences dialog, then Add Filter Group, finally, Add Filter. Paste the above filter into the dialog and click Close. Fan speed should drop considerably. That said, one thing that isn't helping, is that your machine is using the older Merom chip. I noticed on my Dell D830 that going from a 2.2GHz Merom T7500 to a 2.6GHz Penryn T9500 dropped my temperatures by a good 20-50 deg F, depending on how hard the machine is working. I'm not sure what else you'd have to change to get your Santa Rosa board to work with a Penryn chip, but it might be worth checking out, and maybe soldering in a T8300 or similar.



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