OK to run at 100% CPU?

ahostmadsen

macrumors 6502a
Original poster
Dec 28, 2009
751
425
I often run my 2017 15" MacBook Pro for hours at 100% CPU and 100% fan. That ought to be fine, right? But recently I turned in my computer to have the keyboard repaired (yes, sigh), and they found that one fan was dead, and replaced it. So, I wonder if running at extended time at 100% fan really is fine? Anyone else had issues?
 

Airboy1466

macrumors 6502
Feb 23, 2015
326
29
Lol that's like running when tired you will eventually fall out. Or in this circumstance unless you have apple care be paying for various components.
 

mreg376

macrumors 65816
Mar 23, 2008
1,120
309
Brooklyn, NY
There's nothing wrong with running at 100% CPU. And it's rare that Apple's fans die (that goes for us too :)), as they are brushless and should last the life of the machine. So that was a rare failure, in fact it may have never worked. You should not see that happen again.
 

leman

macrumors G3
Oct 14, 2008
9,964
4,550
Yes, its perfectly fine. I have over a dozen of researchers here routinely running their laptops for hours or days (overnight) with statistical analysis (since they are too lazy to learn how to use the supercomputer) and we don't see any abnormal failure rates. Never had a single defect fan issue in over 10 years and I don't even know how many hundreds Macs we went though...

Of course, its all up to personal luck. But if your fan etc. is going to fail, its probably going to fail anyway.
 
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ahostmadsen

macrumors 6502a
Original poster
Dec 28, 2009
751
425
Yes, its perfectly fine. I have over a dozen of researchers here routinely running their laptops for hours or days (overnight) with statistical analysis (since they are too lazy to learn how to use the supercomputer).
That's me! I should learn how to run my statistical analysis on AWS, but unless they're very larger scale, it's easier to just run on my MBP.

Anyway, it seems I was just unlucky with that fan (covered under AppleCare).
 

Trebuin

macrumors 65816
Jun 3, 2008
1,491
266
Central Cali
It's not the continuous running at 100% that kills things, its the fluctuation between cold & hot. For example, if you leave an incandescent lightbulb on for years at a time, it will take years to burn out, but if you turn that bulb on & off at a rate of about 1x every 1-2 seconds, it will probably fail within a few months. Thermal expansion & contraction is what does the most damage.
 
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