By: Linus Torvalds (torvalds.delete@this.linux-foundation.org), December 30, 2020 12:00 pm
Room: Moderated Discussions
Foo_ (foo.delete@this.nomail.com) on December 30, 2020 2:50 am wrote:
>
> Also it is probably not wise to feed more than 16 high-performance cores using
> only two channels of memory.
For a lot of loads, the L3 caches in the chiplets would probably make it work quite well. Yes, you'd get memory-bound, but it might still be worth it to get the extra cores depending on what you do. Caches do work. I think most of what I do would be perfectly fine with just two channels and the kinds of caches the 5000 series has.
I suspect the bigger issue is power delivery and cooling. I think most AM4 processors are specced to 105W TDP (with peak power delivery being another 40% or whatever). Threadrippers are what, 280W TDP?
Yes, if you want to do overclocking, you'll get a AM4 board and heatsink that can do more than the specced power delivery, and maybe it would work fine to push it. But the difference between TDP specs on AM4 and Threadripper is quite noticeable, and I'd expect that to be a more immediate issue.
Linus
>
> Also it is probably not wise to feed more than 16 high-performance cores using
> only two channels of memory.
For a lot of loads, the L3 caches in the chiplets would probably make it work quite well. Yes, you'd get memory-bound, but it might still be worth it to get the extra cores depending on what you do. Caches do work. I think most of what I do would be perfectly fine with just two channels and the kinds of caches the 5000 series has.
I suspect the bigger issue is power delivery and cooling. I think most AM4 processors are specced to 105W TDP (with peak power delivery being another 40% or whatever). Threadrippers are what, 280W TDP?
Yes, if you want to do overclocking, you'll get a AM4 board and heatsink that can do more than the specced power delivery, and maybe it would work fine to push it. But the difference between TDP specs on AM4 and Threadripper is quite noticeable, and I'd expect that to be a more immediate issue.
Linus