There are conflicting reports regarding AVX-512 ability/throughput on the new Skylake-X processors. It is being reported that all non i9 Skylake-X processors only have half the AVX-512 "FMA units" of the i9 variants. However, several benchmarks are showing AVX-512 performance is comparable on the i7-7800X and i9-7900X, (links: http://forum.hwbot.org/showthread.php?t=170550&page=2 http://forum.hwbot.org/showthread.php?t=170550&page=2 and http://www.pcgameshardware.de/Skylake-X-Codename-266252/News/Core-i7-7800X-AVX512-Durchsatz-1232713/ http://www.pcgameshardware.de/Skylake-X-Codename-266252/News/Core-i7-7800X-AVX512-Durchsatz-1232713/ )
Is it possible to comment on this discrepancy? If not, is there documentation on the Skylake-X processors which would resolve this?
Thanks in advance!
avxthrowaway: Thank you very much for joining the Intel® Processors communities.
In order to provide the most accurate response I will do further on this matter. As soon as I gather the information needed I will post all the details on this thread.
Any further questions, please let me know.
I am still waiting for a comment on the original question. Can you please provide a link to the second datasheet for the Skylake-X processors? The first one is here for reference
https://www.intel.com/content/www/us/en/products/processors/core/6th-gen-x-series-datasheet-vol-1.ht... 6th Gen Intel® Core™ X-Series Processor Family Datasheet, Vol. 1
I'm assuming since this product is released, you have the second datasheet and haven't updated your links to it?
I look forward to your response.
/thread/116484 JeffHammond, thank you for your patience.
We have included the AVX count information on https://ark.intel.com/ Intel® Product Specifications
If the Core i7 Skylake X models do in fact have the full AVX512 throughput, I'm curious to know how all the pre-release reviews got it wrong. Where did they get their information from?
If you look at the detailed Skylake Server product pages, you can see that it is clearly marked whether they have 1 or 2 x FMA units: ("# of AVX-512 FMA Units")
- https://ark.intel.com/products/120474/Intel-Xeon-Gold-5120-Processor-19_25M-Cache-2_20-GHz Intel® Xeon® Gold 5120 Processor (19.25M Cache, 2.20 GHz) Product Specifications
- https://ark.intel.com/products/120475/Intel-Xeon-Gold-5122-Processor-16_5M-Cache-3_60-GHz Intel® Xeon® Gold 5122 Processor (16.5M Cache, 3.60 GHz) Product Specifications
But if you look at the product pages for the Skylake X parts, the "# of AVX-512 FMA Units" spec is missing.
- https://ark.intel.com/products/123589/Intel-Core-i7-7800X-X-series-Processor-8_25M-Cache-up-to-4_30-... Intel® Core™ i7-7800X X-series Processor (8.25M Cache, up to 4.30 GHz) Product Specifications
- https://ark.intel.com/products/123613/Intel-Core-i9-7900X-X-series-Processor-13_75M-Cache-up-to-4_30... Intel® Core™ i9-7900X X-series Processor (13.75M Cache, up to 4.30 GHz) Product Specifications
I don't know whether it was intentionally left out or whether it was just an oversight.