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I prefer AMDs approach that allows them to put more cores on the die instead of supporting a rarely used instruction set.
https://www.igorslab.de/en/intel-deactivated-avx-512-on-alde...
Please correct me if I'm wrong, but wouldn't we normally scale these things instead on a GPU?
Intel is removing AVX-512 support from their newer CPU's (Alder Lake +). :/ https://www.igorslab.de/en/intel-deactivated-avx-512-on-alde...
Intel is removing AVX-512 support from their newer CPU's (Alder Lake +). :/ https://www.igorslab.de/en/intel-deactivated-avx-512-on-alde...
Intel is removing AVX-512 support from their newer CPU's (Alder Lake +). :/ https://www.igorslab.de/en/intel-deactivated-avx-512-on-alde...
A problem is slowing down the CPU frequency significantly when AVX-512 is involved, e.g. https://en.wikichip.org/wiki/intel/xeon_gold/6262v this, which usually cancels out the benefit in the Real World (tm).
Earlier quoted context omitted.
Why would it be irrelevant? Even the paucity of availability isn't really a problem - the big winners here are server users in data centers, not desktops or laptops. How much string parsing and munging is happening ingesting big datasets right now? If running a specially optimized function set on part of your fleet reduces utilization, that's direct cost savings you realize. If the AMD is then widening that support b…
Given Intel's AVX extension could cause silent failures on servers (very high work load for prolonged time, compare to end user computers), I'm not sure it would be a big win for servers either: https://arxiv.org/pdf/2102.11245.pdf .
Please correct me if I'm wrong, but wouldn't we normally scale these things instead on a GPU?
The GPU is incredible at raw throughput, and this particular problem can actually implemented fairly straightforwardly (it's a stream compaction, which in turn can be expressed in terms of prefix sum). However, where the GPU absolutely falls down is when you want to interleave CPU and GPU computations. To give round numbers, the roundtrip latency is on the order of 100µs, and even aside from that, the memcpy back and forth between host and device memory might actually be slower than just solving the problem on the CPU. So you only win when the strings are very large, again using round numbers about a megabyte.
Things change if you are able to pipeline a lot of useful computation on the GPU. This is an area of active research (including my own). Aaron Hsu has been doing groundbreaking work implementing an entire compiler on the GPU, and there's more recent work[1], implemented in Futhark, that suggests that that this approach is promising.
I have a paper in the pipeline that includes an extraordinarily high performance (~12G elements/s) GPU implementation of the parentheses matching problem, which is the heart of parsing. If anyone would like to review a draft and provide comments, please add a comment to the GitHub issue[2] I'm using to track this. It's due very soon and I'm on a tight timeline to get all the measurements done, so actionable suggestions on how to improve the text would be most welcome.
[1]: https://theses.liacs.nl/pdf/2020-2021-VoetterRobin.pdf
[2]: https://github.com/raphlinus/raphlinus.github.io/issues/66#i...
Intel is removing AVX-512 support from their newer CPU's (Alder Lake +). :/ https://www.igorslab.de/en/intel-deactivated-avx-512-on-alde...
AVX-512 was never really supported in newer consumer CPUs with heterogeneous architecture. These CPUs have a mix of powerful cores and efficiency cores. The AVX-512 instructions were never added to the efficiency cores because it would use way too much die space and defeat the purpose of efficiency cores.
There was previously a hidden option to disable the efficiency cores and enable AVX-512 on the remaining power cores, but the number of workloads that would warrant turning off a lot of your cores to speed up AVX-512 calculations is virtually non-existent in the consumer world (where these cheap CPUs are targeted).
The whole journalism controversy around AVX-512 has been a bit of a joke because many of the same journalists tried to generate controversy when AVX-512 was first introduced and they realized that AVX-512 code would reduce the CPU clock speed. There were numerous articles about turning off AVX-512 on previous generation CPUs to avoid this downclocking and to make overclocks more stable.