https://bugs.winehq.org/show_bug.cgi?id=56667
--- Comment #7 from dr. Hannibal Lecter neutrinocms@gmail.com --- (In reply to 43615 from comment #6)
However, I'm unable to try it out since that variable doesn't appear to do anything. There's no performance difference and the process log doesn't contain entires about "fill_cpu_override" (as it should according to a googleable post). Does this need a specific Wine version or parameter to function?
Wow, it looks like I was suffering from a major case of placebo yesterday! Turns out, it didn't actually fix things, but my memory of the initial stuttering was twisted so I thought it did something. /facepalm
However, today I went digging a bit more, and found out that WINE_CPU_TOPOLOGY is only a Proton thing, not standard WINE. So I switched to Proton Experimental, and lo and behold, I now have smooth and stable gameplay at 144 FPS!
It also turns out that my hypothesis regarding v-cache cores was also wrong, I'm successfully using all 12 cores of 7900X3D; so if you have an X3D CPU, disregard the comment above regarding v-cache - all physical cores work great.
Thanks for pointing me in the right direction @43615!