5 ms·

Maybe a little surprised - presumably the thermal limitations on a 16 inch laptop are potentially less limiting than on a 13 inch one so that single core could

Maybe a little surprised - presumably the thermal limitations on a 16 inch laptop are potentially less limiting than on a 13 inch one so that single core could be pushed to a higher frequency?

floatingatoll 5y ago
Does the core speed of an M1 core change at all? I thought they used the low/high power cores at fixed-limit clock speeds. It sounds crazy to consider, but maybe they’d rather not try to speed up the individual cores in M1 Max, so that they can keep their overhead competitively low. That certainly would simplify manufacturing and QA; removing an entire vector (clock speed) from the binning process makes pipelines and platforms easier to maintain.
tedunangst 5y ago
For how long? Longer than it takes to run the benchmark?
hajile 5y ago
M1 uses TSMC high-density rather than high-performance. They get 40-60% better transistor density and less leakage (power consumption) at the expense of lower clockspeeds. Also, a core is not necessarily just limited by power. There are often other considerations like pipeline length that affect final target clocks. The fact is that at 3.2GHz, the M1 is very close to a 5800X in single-core performance. When that 5800X cranks up 8 cores, it dramatically slows down the clocks. Meanwhile the M1 should keep its max clockspeeds without any issue. We know this because you can keep the 8 core M1 at max clocks for TEN MINUTES on passive cooling in the Macbook air (you can keep max clocks indefinitely if you apply a little thermal pad on the inside of the case).
- O_H_E 5y ago
  > M1 uses TSMC high-density rather than high-performance. Is that an actual product differentiation from TSMC? Or just observational + the fact that it's 5nm. I'm actually curious from a chip manufacturing standpoint.
  - hajile 5y ago
    There’s actually three major version on N3 (sorry, I don’t have time to look up the similar articles on N5/7, but I think wikichip has a couple). https://www.techdesignforums.com/blog/2021/06/03/three-libraries-tune-speed-and-density-on-tsmcs-3nm-process/ https://www.techdesignforums.com/blog/2021/06/03/three-libra... I remember seeing a picture of a partner list for a TSMC node with a couple dozen libraries that not only changed based on density, but also on type of chip being built.
- klelatti 5y ago
  Maybe this is a reflection of the 16 inches higher thermal envelope? https://www.macrumors.com/2021/10/21/new-macbook-pros-high-power-mode/ https://www.macrumors.com/2021/10/21/new-macbook-pros-high-p...
- runeks 5y ago
  > We know this because you can keep the 8 core M1 at max clocks for TEN MINUTES on passive cooling in the Macbook air (you can keep max clocks indefinitely if you apply a little thermal pad on the inside of the case). Is there a guide on how to apply this thermal pad? I would love for my Air to not downclock. Also why on earth does this thermal pad not come factory installed?
  - qubitcoder 5y ago
    That’s why the MacBook Pro M1 has fans. It’s designed for harder workloads where you’re maxing out the cores (multi-core compilation, video encoding, etc) for extended periods. This was well-documented and discussed previously. The tradeoff is increased heat, power consumption, and fan noise. Realistically, those aren’t typical workloads for most people, especially for 10+ minutes (and especially on an ultralight and portable laptop). So I wouldn’t lose sleep over thermal pads.
- klelatti 5y ago
  Thanks - some very good points. Presumably this opens the possibility of higher single core performance on a future desktop design unless limited by pipeline length etc?
- kllrnohj 5y ago
  > When that 5800X cranks up 8 cores, it dramatically slows down the clocks Not that dramatic, it drops from ~4.8ghz to ~4.4ghz: https://www.anandtech.com/show/16214/amd-zen-3-ryzen-deep-dive-review-5950x-5900x-5800x-and-5700x-tested/8 https://www.anandtech.com/show/16214/amd-zen-3-ryzen-deep-di... Actual drop varying depending on actual power consumption & temperature as Ryzen is more or less an entirely reactive system.

Maybe a little surprised - presumably the thermal limitations on a 16 inch laptop are potentially less limiting than on a 13 inch one so that single core could be pushed to a higher frequency?

floatingatoll 5y ago

Does the core speed of an M1 core change at all? I thought they used the low/high power cores at fixed-limit clock speeds. It sounds crazy to consider, but maybe they’d rather not try to speed up the individual cores in M1 Max, so that they can keep their overhead competitively low. That certainly would simplify manufacturing and QA; removing an entire vector (clock speed) from the binning process makes pipelines and platforms easier to maintain.

tedunangst 5y ago

For how long? Longer than it takes to run the benchmark?

hajile 5y ago

M1 uses TSMC high-density rather than high-performance. They get 40-60% better transistor density and less leakage (power consumption) at the expense of lower clockspeeds. Also, a core is not necessarily just limited by power. There are often other considerations like pipeline length that affect final target clocks. The fact is that at 3.2GHz, the M1 is very close to a 5800X in single-core performance. When that 5800X cranks up 8 cores, it dramatically slows down the clocks. Meanwhile the M1 should keep its max clockspeeds without any issue. We know this because you can keep the 8 core M1 at max clocks for TEN MINUTES on passive cooling in the Macbook air (you can keep max clocks indefinitely if you apply a little thermal pad on the inside of the case).

O_H_E 5y ago
> M1 uses TSMC high-density rather than high-performance. Is that an actual product differentiation from TSMC? Or just observational + the fact that it's 5nm. I'm actually curious from a chip manufacturing standpoint.
- hajile 5y ago
  There’s actually three major version on N3 (sorry, I don’t have time to look up the similar articles on N5/7, but I think wikichip has a couple). https://www.techdesignforums.com/blog/2021/06/03/three-libraries-tune-speed-and-density-on-tsmcs-3nm-process/ https://www.techdesignforums.com/blog/2021/06/03/three-libra... I remember seeing a picture of a partner list for a TSMC node with a couple dozen libraries that not only changed based on density, but also on type of chip being built.
klelatti 5y ago
Maybe this is a reflection of the 16 inches higher thermal envelope? https://www.macrumors.com/2021/10/21/new-macbook-pros-high-power-mode/ https://www.macrumors.com/2021/10/21/new-macbook-pros-high-p...
runeks 5y ago
> We know this because you can keep the 8 core M1 at max clocks for TEN MINUTES on passive cooling in the Macbook air (you can keep max clocks indefinitely if you apply a little thermal pad on the inside of the case). Is there a guide on how to apply this thermal pad? I would love for my Air to not downclock. Also why on earth does this thermal pad not come factory installed?
- qubitcoder 5y ago
  That’s why the MacBook Pro M1 has fans. It’s designed for harder workloads where you’re maxing out the cores (multi-core compilation, video encoding, etc) for extended periods. This was well-documented and discussed previously. The tradeoff is increased heat, power consumption, and fan noise. Realistically, those aren’t typical workloads for most people, especially for 10+ minutes (and especially on an ultralight and portable laptop). So I wouldn’t lose sleep over thermal pads.
klelatti 5y ago
Thanks - some very good points. Presumably this opens the possibility of higher single core performance on a future desktop design unless limited by pipeline length etc?
kllrnohj 5y ago
> When that 5800X cranks up 8 cores, it dramatically slows down the clocks Not that dramatic, it drops from ~4.8ghz to ~4.4ghz: https://www.anandtech.com/show/16214/amd-zen-3-ryzen-deep-dive-review-5950x-5900x-5800x-and-5700x-tested/8 https://www.anandtech.com/show/16214/amd-zen-3-ryzen-deep-di... Actual drop varying depending on actual power consumption & temperature as Ryzen is more or less an entirely reactive system.