Tackling the Heat Issue on M2 Max MBP: Exploring Thermal Solutions

[sunlit]

I got new macbook pro 16" with M2 Max and it was running very cool (actually with fans at 0 RPM most of the time even video editing in Final Cut!) but that was until I started Lightroom Classic preview generation. Thats when I saw core temps peak at 108C and throttling and the fans started to rev up but never beyond 3,000 RMP (which is still pretty quiet, and they can spin up to 6,000). So to anyone doubting throttling and high cpu core temps - just run Lightroom with several thousand pics in the library and tell it to generate standard sized previews for several thousand pics. That brings cpu usage up to 50-90% and thats where the heat starts!

 

[DHagan4755]

until I started Lightroom Classic

Sounds like Adobe's software is not optimized for Apple silicon. Do these issues happen in Capture One or other competitive photo editing software? I'm curious.

 

[kitKAC]

Apparently it is.

https://petapixel.com/2021/06/08/performance-test-lightroom-classic-is-way-faster-on-apple-silicon/

 

[iMacDragon]

It is, it's just capable of fully expoiting parallel processing to use all resources when doing the processing. Anything that can fully utilise system will certainly get things hot. It's just most things do every day are either short and bursty, or single threaded, so won't get things quite as hot.

 

[sunlit]

Sounds like Adobe's software is not optimized for Apple silicon. Do these issues happen in Capture One or other competitive photo editing software? I'm curious.

Well it depends on how you look at it. Final Cut is super optimized - it can run with fans at 0 rpm - but that means it is not utilizing the hardware 100%. Also Final Cut is mostly relying on GPU - full GPU utilization does not bring the temps up that high. However, any software that would load all CPU cores close to 100% will produce high core temperatures! So we can say that Lightroom is optimized more towards performance - it loads both GPU and CPU and consequently we are seeing eye ball rolling 108C on the M2Max cores. Also bear in mind that you reach those scorching temps only when macbook is set to "performance" setting. If left at "auto" it is more cool (and a bit slower also I would presume, but that needs testing)

 

[Andropov]

Well it depends on how you look at it. Final Cut is super optimized - it can run with fans at 0 rpm - but that means it is not utilizing the hardware 100%.

Not really. Rule #1 of software optimization is not "use more of the hardware", but rather "do less work for the same result".

For example, if I'm not caching a commonly accessed and expensive to compute value, I could end up with all cores at 100% recomputing that value over and over again. If I cache the value, and keep track of when the value could (potentially) have changed to invalidate the cache only then, the amount of work done could go down to near zero. Yet the former is not optimized towards performance, it's just less optimized.

 

[dmccloud]

Well it depends on how you look at it. Final Cut is super optimized - it can run with fans at 0 rpm - but that means it is not utilizing the hardware 100%. Also Final Cut is mostly relying on GPU - full GPU utilization does not bring the temps up that high. However, any software that would load all CPU cores close to 100% will produce high core temperatures! So we can say that Lightroom is optimized more towards performance - it loads both GPU and CPU and consequently we are seeing eye ball rolling 108C on the M2Max cores. Also bear in mind that you reach those scorching temps only when macbook is set to "performance" setting. If left at "auto" it is more cool (and a bit slower also I would presume, but that needs testing)

I have done some testing on my 14" MBP between Low Power mode and normal mode (No performance mode on the 14" M2 Max, only the 16"), and while benchmarks such as Cinebench R23 and Geekbench 5 & 6 showed a noticeable drop in performance, I have yet to notice that in real-world usage (unless I'm running multiple VMs at once, which is an entirely other issue).

 

[ascender]

Can I just ask if anyone has used a 14" M1 Max and a 14" M2 Max and can comment on their temperatures under normal load - i.e. not doing anything which is nailing the CPU and/or GPU?

I used an M1 Max for a while and the bottom of the laptop got warm under what I'd say was normal use - compared to an M1 Pro which didn't warm-up until I pushed it a bit causing the fans to come on.

I was just wondering if the M2 Max situation has improved at all as we need to get a new laptop with 32GB RAM and that either means an M2 Max or a BTO M2 Pro.

Thanks!

 

[dmccloud]

Can I just ask if anyone has used a 14" M1 Max and a 14" M2 Max and can comment on their temperatures under normal load - i.e. not doing anything which is nailing the CPU and/or GPU?

I used an M1 Max for a while and the bottom of the laptop got warm under what I'd say was normal use - compared to an M1 Pro which didn't warm-up until I pushed it a bit causing the fans to come on.

I was just wondering if the M2 Max situation has improved at all as we need to get a new laptop with 32GB RAM and that either means an M2 Max or a BTO M2 Pro.

Thanks!

Core temps on my 14" MBP (M2 Max) hover in the 32-33C range and the fans are at 0 RPM when browsing the internet, reading forums such as this one, or watching YouTube videos. Given that TJMax for most CPUs/SoCs is between 90C and 100C, there's a lot of thermal headroom left over. I have yet to run into a situation where thermals became a concern, even when running Cinebench in a stress test mode, rendering 4k videos, or compiling large sections of code.

 

[ascender]

Core temps on my 14" MBP (M2 Max) hover in the 32-33C range and the fans are at 0 RPM when browsing the internet, reading forums such as this one, or watching YouTube videos. Given that TJMax for most CPUs/SoCs is between 90C and 100C, there's a lot of thermal headroom left over. I have yet to run into a situation where thermals became a concern, even when running Cinebench in a stress test mode, rendering 4k videos, or compiling large sections of code.

Thanks for taking the time to reply with your experience!

 

[Fuchal]

Core temps on my 14" MBP (M2 Max) hover in the 32-33C range and the fans are at 0 RPM when browsing the internet, reading forums such as this one, or watching YouTube videos. Given that TJMax for most CPUs/SoCs is between 90C and 100C, there's a lot of thermal headroom left over. I have yet to run into a situation where thermals became a concern, even when running Cinebench in a stress test mode, rendering 4k videos, or compiling large sections of code.

I have the same system and the same experience.