Just built my first ever AMD Epyc workstation and it's working great! Was a bit hesitant to go this route, Epyc motherboards are only validated for Windows Server OS, but they apparently run Windows 10/11 without issues.
Installing these huge CPUs is not for the faint of heart, only consider this if you're experienced building and maintaining regular size systems.

And here's Avid using 100% of 32 CPU cores: Complete specs: GENOAD8X-2T/BCM, Epyc 9334, KINGSTON 4800 1RX8 HYNIX A, WD BLACK SN850 NVMe, RTX 4070 TI SUPER, MegaRaid 9560, Mellanox ConnectX-4 Lx

Nice. Though, I think MC's threading peaks at 32 threads. So, anything higher might reduce performance.

Hmm, yeah, there might be truth to that, but are you sure that's not just an artifact of hyper-threading not making much sense anymore or maybe the reduced clocks on higher core counts? With this system saturating so well, I'd hazard a guess that 64 cores should work pretty well for both background and foreground transcoding simultaneously.

The main reason I went the Epyc route is that I should be able to upgrade to a next-gen 64-core part with better clocks and IPC, used for cheap, in 4–5 years - plus the 7 PCIe slots ;-)

I can't remember where I read the 32-thread recommendation, but I think it was one of the Avid Windows configuration guides. It might be 64 as Avid does approve of dual 32-core CPU config.

Yeah, Avid specs always favor the highest turbo for snappiness, I'd say. Whats curious, is that hey suggest hyper-threading for an Intel 32-core part they recommend, but favor a 32-core Threadripper over a 64-core part with only marginally worse clocks. Either way, when I update the CPU to 64 cores in the future, I'll get more clocks as well, so this should be fine.