Should I be worried about these CPU temps?

[pullman]

Hello Mac fans

My beloved 11" MBA (2015, i7) was recently given a new lease of life with an NVME because the original SSD died. It runs generally very well but I have noticed that the fans rev up slightly more often than before. I installed Macs Fan Control and noticed that the CPU temps sometimes hit 100+ Centrigrades.

Is this a cause for concern? Oddly enough that level of temperature cannot be felt on the underside of the notebook. It only becomes cozily warm, not hot to the touch.

Thanks in advance for your thoughts
Philip

 

[Technerd108]

Since it is an older laptop with a pretty old cpu this is normal considering Apple's cooling solution was never very good.

It is running hot no doubt but probably not too hot to cause damage. Over time running at these temps the cpu could have issues or the integrated gpu.

If it is a big concern for you then a laptop cooler with a few fans may help. Running in low power mode will reduce cpu frequencies and may also help.

Good Luck!

 

[Howard2k]

It depends what the laptop was doing. Those temps while sitting idle are absolutely a concern.

 

[Alpha Centauri]

I'd consider repasting the CPU after 10 years of service. My considerably older MBP benefited by an average 10 degree (C) drop immediately, fans were coming on less frequently and the lower case did become warmer afterwards as the heat was effectively transferred.

 

[pullman]

Since it is an older laptop with a pretty old cpu this is normal considering Apple's cooling solution was never very good.

It is running hot no doubt but probably not too hot to cause damage. Over time running at these temps the cpu could have issues or the integrated gpu.

If it is a big concern for you then a laptop cooler with a few fans may help. Running in low power mode will reduce cpu frequencies and may also help.

Good Luck!

Thank you for the suggestions. I'm not sure it's possible to run this in low power mode unfortunately. I'm using Monterey on this machine.

 

[pullman]

It depends what the laptop was doing. Those temps while sitting idle are absolutely a concern.

Thank you Howard, the CPU reaches that temperature when for instance streaming on YouTube. At the moment I'm writing this (with five tabs open in Safari plus Davinci Resolve and MS Word open in the background) the CPU temps vary between 55C and 75C.

 

[pullman]

I'd consider repasting the CPU after 10 years of service. My considerably older MBP benefited by an average 10 degree (C) drop immediately, fans were coming on less frequently and the lower case did become warmer afterwards as the heat was effectively transferred.

Thank you for the suggestion. I hadn't thought of that. I think I have some of that Silver-something somewhere actually.

 

[bzgnyc2]

Thank you Howard, the CPU reaches that temperature when for instance streaming on YouTube. At the moment I'm writing this (with five tabs open in Safari plus Davinci Resolve and MS Word open in the background) the CPU temps vary between 55C and 75C.

That doesn't too bad for the situation. 100 deg C would have been high for idle as someone mentioned. At complete idle, I'd look for a CPU PECI ~ 50 deg C perhaps less.

It sounds like in your case that Youtube streaming is driving your CPU to full blast. You can check your CPU utilization during streaming with Activity Monitor. If so my guess is that Youtube is not streaming video to you in a format that makes use of your CPU's hardware video decoding. That CPU appears to support up to VP8 while a lot of streaming these days is in H.264/AVC or VP9 (or newer). You can gets the details on Youtube's streaming to you including the codec via their "Stats For Nerds" viewer available in the menu you get by right-clicking on the video while viewing it. If it's somethig like AVC or VP9, that's going to drive your CPU.

If something else, post for others who know the various codec formats and implications for different generations of CPU to advise on here. Also if anyone can suggest ways to steer Youtube to VP8 or something else that works better with the CPU in that MacBook.

P.S.Repasting the CPU, etc as others have mentioned may also be a good idea.

 

[pullman]

That doesn't too bad for the situation. 100 deg C would have been high for idle as someone mentioned. At complete idle, I'd look for a CPU PECI ~ 50 deg C perhaps less.

It sounds like in your case that Youtube streaming is driving your CPU to full blast. You can check your CPU utilization during streaming with Activity Monitor. If so my guess is that Youtube is not streaming video to you in a format that makes use of your CPU's hardware video decoding. That CPU appears to support up to VP8 while a lot of streaming these days is in H.264/AVC or VP9 (or newer). You can gets the details on Youtube's streaming to you including the codec via their "Stats For Nerds" viewer available in the menu you get by right-clicking on the video while viewing it. If it's somethig like AVC or VP9, that's going to drive your CPU.

If something else, post for others who know the various codec formats and implications for different generations of CPU to advise on here. Also if anyone can suggest ways to steer Youtube to VP8 or something else that works better with the CPU in that MacBook.

P.S.Repasting the CPU, etc as others have mentioned may also be a good idea.

Thank you for the suggestions. I didn't know that above decoding actually.

I've done a bit more testing and it seems the CPU temps vary a great deal from one moment to the next. For instance, if upon reboot I launch Messages, Notes, Calendar and Safari and then open, say, six tabs in Safari the temps will fly up to 100+ right away. But within seconds of the programs having launched the temps drop to around 60C. If I start streaming something they go up towards 90C but then drop down to 70-80C. Btw, this is after putting new Arctic Silver on the CPU.

I suppose all this is because of the age of the computer and because it is, after all, a rather weak CPU and GPU infrastructure. As long as the computer isn't a fire hazard I'm happy.

 

[Howard2k]

Thank you for the suggestions. I didn't know that above decoding actually.

I've done a bit more testing and it seems the CPU temps vary a great deal from one moment to the next. For instance, if upon reboot I launch Messages, Notes, Calendar and Safari and then open, say, six tabs in Safari the temps will fly up to 100+ right away. But within seconds of the programs having launched the temps drop to around 60C. If I start streaming something they go up towards 90C but then drop down to 70-80C. Btw, this is after putting new Arctic Silver on the CPU.

I suppose all this is because of the age of the computer and because it is, after all, a rather weak CPU and GPU infrastructure. As long as the computer isn't a fire hazard I'm happy.

No, it'll thermally throttle and sounds like it's working as expected. Nice move on the thermal paste, should extend the life.

 

[bzgnyc2]

Thank you for the suggestions. I didn't know that above decoding actually.

I've done a bit more testing and it seems the CPU temps vary a great deal from one moment to the next. For instance, if upon reboot I launch Messages, Notes, Calendar and Safari and then open, say, six tabs in Safari the temps will fly up to 100+ right away. But within seconds of the programs having launched the temps drop to around 60C. If I start streaming something they go up towards 90C but then drop down to 70-80C. Btw, this is after putting new Arctic Silver on the CPU.

Yes I wouldn't pay much attention to the moment-to-moment temperatures of the individual CPU cores or CPU PECI. The nature of these systems is to run the CPU at 100% when you do something so that it can respond to you as quickly as possible. Then return to ~ idle while it waits for your next request. The nature of most people's demands on their computers these days is long periods strolling occasionally interrupted by sprints. These CPUs take advantage of that to not run all out most of the time allowing for quick boosts in order to be responsive when needed.

Software video encoding or decoding, 3D rendering, etc are a little different in that the demand on the CPU is naturally extended. Then the systems will find a steady state to run the CPU as fast as possible without overheating.

100 deg C is generally the target temperature for individual cores. Sometimes I'll see the system play 'hot potato' with a CPU intense thread/process -- bouncing it between cores so that some can cool while one runs to max. In any case these temperatures are normal for a CPU core while the system is running all out -- even if just for a few seconds.

Then I would look at the CPU Proximity values instead to see how things are 'averaging'.

I suppose all this is because of the age of the computer and because it is, after all, a rather weak CPU and GPU infrastructure. As long as the computer isn't a fire hazard I'm happy.

As long as the temperature sensors are working it should be fine. Keeping the cooling system optimal like you've done should allow it to run cooler all else being equal and otherwise reduce "thermal throttling" when you drive it all out.