SMT performance impact in games on Ryzen CPUs?

[g67575]

Does SMT improve minimum framerates in most titles?

Tried to find specific info on this for Zen 4, but none available yet.

I'm going to have an AM5 board soon + 8 core 7700X, so I'm curious about what the impact of leaving SMT enabled in games is.

I've seen some games perform badly with it enabled on previous Ryzen generations, like AC: Odyssey.

Hyperthreading on my 10700KF can significantly reduce minimum framerates, in games like TW: Warhammer III, which apparently is not optimised to use lots of threads.

 

[Rroff]

Any form of SMT (including HT) can result in slightly lower minimum frame rates - usually it shouldn't be more than 5% impact but you might find the odd application which doesn't like it at all. Net gain is a significant advantage to having it enabled though - especially games where you are running above 60 FPS and desktop use in general it helps to keep everything smooth and responsive.

AMD have paid a bit more attention to latency especially cross core, etc. on 5000 series CPUs (and onward) which does help to reduce some negatives you might see with games on older Ryzen CPUs.

 

[g67575]

It looks like AMD drew the short straw when it comes to multithreaded optimisation, at least in games. In Cyberpunk, the developers seemed to struggle with SMT optimization:

Reddit - Dive into anything

www.reddit.com

In the 2nd screenshot, SMT utilization is much greater across all cores of the 5800X3D, with a significant increase in FPS and GPU utilization.

 

[Rroff]

CP2077 doesn't run that amazing, even with patches, on AMD CPUs really - it seems to have been optimised on older Intel workstation CPUs (possibly the development boxes) or something as I get much more consistent performance with my older Xeon, than a newer 10th gen CPU! with the same GPU.

EDIT: Well that and it loves memory bandwidth.