Re:AMD’s aggressive pricing update on the EPYC 7371
by bitL on Friday December 07, 2018 @10:12AM
(#18628271)
Yes, but a slow one. They just bump AVX units from 128-bit to 256-bit, making it Haswell-style. Skylake-X has a full 512-bit wide AVX unit.
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Re:AMD’s aggressive pricing update on the EPYC 7371
by bpye on Friday December 07, 2018 @11:13AM
(#18628846)
Doesn't Skylake-X have the whole downclocking issue when running AVX-512 workloads though? Unless you can use almost exclusively AVX-512 then it doesn't make sense.
https://blog.cloudflare.com/on-the-dangers-of-intels-frequen...
Re:AMD’s aggressive pricing update on the EPYC 7371
by gameswithgo on Friday December 07, 2018 @01:10PM
(#18630009)
AVX and AVX512 both do downclocking.
Likely AMD will have to downclock too, pretty fundamental limits at work there.
Re:AMD’s aggressive pricing update on the EPYC 7371
by hajile on Friday December 07, 2018 @05:29PM
(#18632278)
AMD verified they would be running AVX2 at full clocks. Doing AVX-512 would happen at half-rate, but the processor would continue at full speed. In contrast, skylake downclocks base clocks by 30+%.
Not only does the AVX calculation downclock, but all the other calculations in other ALUs/FPUs also downclock. For pure AVX-512 workloads, Intel would be a little faster, but for mixed loads, AMD should be much faster overall.
AMD says they don't downclock AVX2 (about 2/5 down the page)
https://www.anandtech.com/show/13578/naples-rome-milan-zen-4...
See page 13 for AVX clockspeeds
https://www.intel.com/content/dam/www/public/us/en/documents...
Re:AMD’s aggressive pricing update on the EPYC 7371
by bitL on Friday December 07, 2018 @04:24PM
(#18631827)
With 7nm they might not need to downclock that much.