amd EPYC (server)
 

[url]http://www.tomshardware.com/news/amd-epyc-processor-models-pricing,34833.html[/url]

from 8/16 core /thread to 32/64 with a base freq of 2.0/2.4 Ghz, 8 DDram4 channel and 128 PCIe lane. TDP between 120 and 180 W

[QUOTE=firejuggler;462047][url]http://www.tomshardware.com/news/amd-epyc-processor-models-pricing,34833.html[/url]

from 8/16 core /thread to 32/64 with a base freq of 2.0/2.4 Ghz, 8 DDram4 channel and 128 PCIe lane. TDP between 120 and 180 W[/QUOTE]

Although it would be ridiculously expensive, I was looking at the Epyc 7251, which has 8 cores/ 16 thread, with 8 channels or DDR4 !! It would be fascinating to run a comparison
to the Ryzen 7 that has faster clocks, but only 2 channel ram. Slower cpu speed with better memory access just might be enough to keep the cores from stalling due to memory starvation.

[QUOTE=tServo;462371]Although it would be ridiculously expensive, I was looking at the Epyc 7251, which has 8 cores/ 16 thread, with 8 channels or DDR4 !! It would be fascinating to run a comparison
to the Ryzen 7 that has faster clocks, but only 2 channel ram. Slower cpu speed with better memory access just might be enough to keep the cores from stalling due to memory starvation.[/QUOTE]

The other thing to remember is that there are 2 channels per die, with one core per CCX per die in the 8 core model. It's probable the kernel will allocate memory all on the two channels connected to one CCX.

My guess is that two workers on Threadripper and four workers on Epyc will be optimal, regardless of the core counts.