[CoolGuySteve]

We already saw that the Threadripper 2990 is starved for bandwidth between Zen packages due to the infinity fabric design.

So you get incredible cinebench performance (and some other 'embarrassingly parallel' workloads), but it doesn't scale to other kinds of programs that have more interthread/interprocess communication.

I guess it remains to be seen what happens with EPYC, but my initial guess is that it will have a similar infinity fabric design to hit 64 cores/128 hyperthreads.

BTW has anyone done an R mclapply benchmark on Threadripper 2990? I was set to buy one until I saw the uneven benchmark scores.

[TheGuyWhoCodes]

Yes, infinity fabric has limitations. Threadripper suffers in memory intensive workloads because only half of the CCXs have a dedicated memory controller thus some cores need to talk to another CCX to access memory. On EPYC each CCX has its own memory controller so it's less of an issue.

[jesuslop]

Bad interthread is tolerable as long as concurrent running from cache is good