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MBP 2015 running very hot: Firefox the culprit?

Mais78

macrumors regular
Original poster
Dec 1, 2014
249
26
Hi, my MBP 2015 quite often runs very hot (even though the fans rarely kick in). Not sure if I should be worried or not (what is too hot? Is the heath damaging the battery?).

I think the culprit is Firefox, if i look in the activity monitor CPU usage is easily 70-85%, sometimes even over 100%. On the other hand Safari seems very gentle on CPU. The thing is I prefer Firefox as I can sync bookmarks and passwords across my computers (including Windows at work), I also like the fact that with Firefox I can set up a Master password for increased security.

So I tried disabling hardware acceleration (both in FF settings and Flash settings) and also disabled all add-ons, but it does not seem to help.

Any solution?
Thanks
 

snaky69

macrumors 603
Mar 14, 2008
5,904
484
Define hot.

Hot to the touch means nothing, nobody has the same tolerance to heat.

CPU usage is high for just browsing. You were probably watching flash based video?
 

joe-h2o

macrumors 6502a
Jun 24, 2012
997
445
Hi, my MBP 2015 quite often runs very hot (even though the fans rarely kick in). Not sure if I should be worried or not (what is too hot? Is the heath damaging the battery?).

I think the culprit is Firefox, if i look in the activity monitor CPU usage is easily 70-85%, sometimes even over 100%. On the other hand Safari seems very gentle on CPU. The thing is I prefer Firefox as I can sync bookmarks and passwords across my computers (including Windows at work), I also like the fact that with Firefox I can set up a Master password for increased security.

So I tried disabling hardware acceleration (both in FF settings and Flash settings) and also disabled all add-ons, but it does not seem to help.

Any solution?
Thanks

Yes, Firefox will use a lot more CPU than Safari - it's just how it is for Chrome and Firefox on Mac. Apple did a great job making Safari sip power when it's working.

Disabling hardware acceleration will make the heating much, much, much *worse* since you're forcing the CPU to software render things that the GPU/iGPU can do trivially for almost no cost but that cost the CPU quite a lot of cycles. Turn all the hardware acceleration back on.

Either way though, the use of Firefox and Flash (especially) will cause your machine to heat up since the CPU will be working hard.
 

0983275

Suspended
Mar 15, 2013
472
56
I run Firefox and I've never experienced the problems you're having except when I'm using Flash, try starting up Firefox in safe mode and use it for a bit, see if it helps.

The only time I experience the problems you're having is when I'm running Chrome, but then again Chrome is known for being a massive resource hog on OS X.
 

Mais78

macrumors regular
Original poster
Dec 1, 2014
249
26
Thanks, what % of CPU does your Firefox normally use?
 

Dark Void

macrumors 68030
Jun 1, 2011
2,614
478
It would help to list a temperature in order for us to help confirm if it is normal or not. In all likelihood if you're not physically burning yourself or if the components aren't shutting themselves down then you're fine.
 
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