By: justcurious (firstname.lastname@example.org), December 1, 2018 3:18 pm
Room: Moderated Discussions
ServeTheHome.com has published many Epyc vs Xeon Gold comparisons and one of their benchmark of choices is Gromacs, a simulation software heavily tuned for either AVX512 or AVX2. The win always goes to Intel as their cores have a dual AVX512 unit. But looking more closely to the benchmark results leads to a weird picture, to whit:
Intel Gold 6134: 8 cores, each with L2 1MB, L3 3MB+, 32 F64 ops per cycles (FMA), and sharing 3/4 of a memory port.
AMD Epyc 7601: 32 cores, each with L2 0.5MB, L3 2MB, 8 F64 ops per cycles and sharing 1/4 of a memory port.
Intel 8 * 32 = 32 * 8 AMD on the peak F64 per cycle.
The Intel runs at 2.7 GHZ under AVX512 while the AMD runs at 2.2 GHZ
In other words, the Intel cpu has better specs in every department and with the added advantage of running one fourth of the cores at a 500MHZ higher clock, the Xeon should crush the Epyc cpu at Gromacs.
And yet the Xeon scores 49.4, slightly below the Epyc cpu at 49.5.
On frequency alone the Xeon score should be above 60 if it had the same efficiency (Gromacs / flops) as the Epyc cpu, so this begs the question: Is the AVX512 worth its weight in transistors and infrastructure support?