5 ms·

Yes. I am working on updating it.

jacobolus 6y ago
Thanks for a quick fix on a Sunday afternoon! I’m impressed that the M1 can keep up on this SIMD-optimized code, likely at much lower temperature / power use. And even the Rosetta numbers are pretty decent.
- bfgoodrich 6y ago
  The post with egregious errors was also put up on a Sunday afternoon. And while we're all acting conciliatory now, it's pretty remarkable how biased the post was, the author using some clearly erroneous numbers to prove their prior, baseless claim that the "M1 chip is far inferior" in some respects, when those respects were specifically SIMD. Then becoming strangely defensive when some people rightly pointed out that ARM64 has 128-bit NEON and a number of other advantages. Far inferior becomes....actually superior in many cases, even at SIMD.
  - jacobolus 6y ago
    Let’s try to be charitable, shall we? Everyone makes mistakes sometimes, even leading experts in low-level algorithm optimization. Lemire was upfront about making a mistake, and not at all defensive about it; if you are reading it that way, it’s just you. It is clearly the case that the M1 CPU/SoC has a significant performance advantage in typical branchy single-core code, but much less advantage if any for certain kinds of heavily optimized numerics. Beyond that high-level summary, it’s good to dive into the details, and spark discussions. Everyone is just now getting their hands on these chips, learning how to work with them, and trying to figure out how to best optimize for them.
    - bfgoodrich 6y ago
      After the original post, several people pointed out some pretty significant, breaking mistakes. For instance the claim that the Apple chip has "nothing of the sort" compared to the SIMD on the Intel chip, making it "far inferior [in some respects]". It seems dubious that someone cognizant of the 128-bit NEON instructions would say such a thing. The follow-up post then defensively used pejorative language to describe those people, such as that they were "rubbed the wrong way", among other dismissive lines, pointing to some prior entry to prove that surely he isn't unaware of such a thing, then going into the demonstration with the intention of proving his original point. That's...not useful. He made an enormous error because he was certain that his original wrong claims must be true. I'm not surprised that he recanted given that it was a pretty embarrassing, egregious error seen by thousands.
deleted 6y ago
[deleted]
acqq 6y ago
So the updated values on the original page are now: > Intel/M1 ratio 1.2 0.9 > As you can see, the older Intel processor is slightly superior to the Apple M1 in the minify test. I'd consider it as bigger news that M1 in one of the two tests chosen by the author (utf8) 10% faster than Intel, and in another (minify) only 20% slower, which is for most purposes something that most users won't even be able to notice. It's quite remarkable result. I'd surely write: "As you can also see, in the UTF-8 validate test M1 is superior to older Intel processor, and in the minify test only 20% slower, even if Intel uses more power to calculate the result!" ----- (Additionally I use the opportunity to thank again to u/bacon_blood who verified the initial claims and u/messe who figured out what the remaining bug in the author sources was! Great work!) (Edit: the ratio 1.16 is from older native measurement. So I've also made an error in the previous version of this comment! I've wrongly connected that with the Rosetta 2 produced code. I've deleted that part of this message. Still the difference between 1.07 and 0.9 measured on two different setups is interesting, when another test is close enough).
- macintux 6y ago
  Yeah, the tone of the post still reflects the original results, and the update should be at the top for anyone returning to it later. Still, glad this was caught.
kergonath 6y ago
Thank you. The whole discussion (starting from your original post) is very useful and interesting.

Thanks for a quick fix on a Sunday afternoon! I’m impressed that the M1 can keep up on this SIMD-optimized code, likely at much lower temperature / power use. And even the Rosetta numbers are pretty decent.

bfgoodrich 6y ago
The post with egregious errors was also put up on a Sunday afternoon. And while we're all acting conciliatory now, it's pretty remarkable how biased the post was, the author using some clearly erroneous numbers to prove their prior, baseless claim that the "M1 chip is far inferior" in some respects, when those respects were specifically SIMD. Then becoming strangely defensive when some people rightly pointed out that ARM64 has 128-bit NEON and a number of other advantages. Far inferior becomes....actually superior in many cases, even at SIMD.
- jacobolus 6y ago
  Let’s try to be charitable, shall we? Everyone makes mistakes sometimes, even leading experts in low-level algorithm optimization. Lemire was upfront about making a mistake, and not at all defensive about it; if you are reading it that way, it’s just you. It is clearly the case that the M1 CPU/SoC has a significant performance advantage in typical branchy single-core code, but much less advantage if any for certain kinds of heavily optimized numerics. Beyond that high-level summary, it’s good to dive into the details, and spark discussions. Everyone is just now getting their hands on these chips, learning how to work with them, and trying to figure out how to best optimize for them.
  - bfgoodrich 6y ago
    After the original post, several people pointed out some pretty significant, breaking mistakes. For instance the claim that the Apple chip has "nothing of the sort" compared to the SIMD on the Intel chip, making it "far inferior [in some respects]". It seems dubious that someone cognizant of the 128-bit NEON instructions would say such a thing. The follow-up post then defensively used pejorative language to describe those people, such as that they were "rubbed the wrong way", among other dismissive lines, pointing to some prior entry to prove that surely he isn't unaware of such a thing, then going into the demonstration with the intention of proving his original point. That's...not useful. He made an enormous error because he was certain that his original wrong claims must be true. I'm not surprised that he recanted given that it was a pretty embarrassing, egregious error seen by thousands.

deleted 6y ago

[deleted]

acqq 6y ago

So the updated values on the original page are now: > Intel/M1 ratio 1.2 0.9 > As you can see, the older Intel processor is slightly superior to the Apple M1 in the minify test. I'd consider it as bigger news that M1 in one of the two tests chosen by the author (utf8) 10% faster than Intel, and in another (minify) only 20% slower, which is for most purposes something that most users won't even be able to notice. It's quite remarkable result. I'd surely write: "As you can also see, in the UTF-8 validate test M1 is superior to older Intel processor, and in the minify test only 20% slower, even if Intel uses more power to calculate the result!" ----- (Additionally I use the opportunity to thank again to u/bacon_blood who verified the initial claims and u/messe who figured out what the remaining bug in the author sources was! Great work!) (Edit: the ratio 1.16 is from older native measurement. So I've also made an error in the previous version of this comment! I've wrongly connected that with the Rosetta 2 produced code. I've deleted that part of this message. Still the difference between 1.07 and 0.9 measured on two different setups is interesting, when another test is close enough).

macintux 6y ago
Yeah, the tone of the post still reflects the original results, and the update should be at the top for anyone returning to it later. Still, glad this was caught.

kergonath 6y ago

Thank you. The whole discussion (starting from your original post) is very useful and interesting.