Tuesday, July 5, 2022 [Tweets] [Favorites]

M2 Mac Thermal Concerns

Vadim Yuryev (video):

We discovered SEVERE thermal throttling with Apple’s new M2 MacBook Pro, proving that it needs a BETTER cooling system with two fans instead of one. We exported 8K Canon RAW and saw temps hit 108°C, more than we’ve ever seen on a Mac, even an Intel Mac.

[…]

The fan was maxed out at 7200RPM the ENTIRE time, so there was nothing the MacBook Pro could do to cool itself down except for HEAVILY throttle down the M2 chip. This led to much worse performance than the M1 Pro chip, which didn’t have to max out its fans.

Via Marco Arment:

This is concerning if it’s not a fluke.

It suggests that M2 thermal load is higher than M1 by enough to warrant different cooling needs (and different buying decisions) if your workload heavily stresses the GPU.

Curious about the Air. 30W seems like too much to passively cool.

Previously:

Update (2022-07-06): See also: Hacker News.

Gary and Hardware Unboxed have not been able to reproduce the problem.

Update (2022-07-10): See also: Accidental Tech Podcast.

9 Comments

"This led to much worse performance than the M1 Pro chip, which didn’t have to max out its fans."

They’re claiming the throttling is leading to the performance difference? How about the different number of performance cores?

This is pure clickbait to make it sound like the M2 is worse than the M1. How about actually comparing it to an M1 then?

Throttling sounds bad, but the other way of looking at it is just more aggressive turbo boost. What counts is the sustained performance and heat compared to M1 (not compared to a better cooled and bigger M1 Pro).

Bold claim for something they tested on a sample of one. Not worth amplifying until there’s more evidence imho.

@Nik There is a later test with the regular M1 in the 13-inch MacBook Pro. Comparing the base models of the current and previous generation seems like a fair and relevant test to me. In this case, the M2 was slightly faster, though the throttling behavior was very different between the two Macs.

"This is pure clickbait to make it sound like the M2 is worse than the M1. How about actually comparing it to an M1 then?"

did you miss the part where it reached 108 degrees Celsius, or did you forget to turn off your RDF?

I'm a bit confused by this.

> We discovered SEVERE thermal throttling with Apple’s new M2 MacBook Pro, proving that it needs a BETTER cooling system with two fans instead of one.

This doesn't logically follow. I guess what they're saying is "providing evidence that, with a better cooling system, it could sustain performance for longer".

>The fan was maxed out at 7200RPM the ENTIRE time, so there was nothing the MacBook Pro could do to cool itself down except for HEAVILY throttle down the M2 chip.

Does the 28-minute video actually show a line chart that proves that performance goes down after a while? I tried scrubbing through it, but turns out video is an astonishingly bad medium to use here. I'll wait for the Anandtech article, which will presumably also have fewer superlatives.

>temps hit 108°C, more than we’ve ever seen on a Mac, even an Intel Mac.

Given that Intel chips are rated to max out at 100, that's not very surprising. It also isn't very relevant. Neither is the comparison with the M1 Pro. A comparison with a 13-inch M1 would've made more sense.

Leaving all this aside: I'm a bit puzzled by the presumed findings. So a chip that's mostly an iteration of the previous chip, on the same process node but slightly improved, at a higher clock, should perform just as well if not better as its predecessor. It may have slightly worse thermals because they clock it higher, but those should in turn also lead to slightly better performance. Conversely, as soon as it overheats, it should simply clock down slightly to revert to a behavior more closely to the M1.

Perhaps the missing piece of the puzzle are the different video transcoding cores. Maybe there's a firmware bug in those.

> did you miss the part where it reached 108 degrees Celsius

That's high, but not dramatically high, for a laptop CPU. AMD Ryzen R7 5800H is rated at up to 105.

I think this is a fluke. People can’t reproduce those thermals. Sounds like an unfortunate lemon situation.

https://twitter.com/every_daydad/status/1542534316433068033?s=21&t=V9RzH5QcS8iKDOtRbiJmjQ

Hardware Unboxed, who I trust for notebook performance reviews, found no such problem:
https://www.youtube.com/watch?v=FWfJq0Y4Oos

@ Plume: thanks; I watched that in its entirety and it matches with what I expected.

Given that the M2 launched 19 months after the M1, it's not a very impressive upgrade, but not terrible either. Hopefully, the M3 is more substantial.

The other concerning thing that was in that MaxTech video was that the cores were clocked higher, but didn't seem to be hitting those higher clocks even when the machine was cool.

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