12900K (Alder Lake) for GPU-passthru VM, good or bad idea?

[8-P]

So I finally decided to make the jump from my trusty old 8700K / GTX1080 and went kinda big…

How big? 12900K, RTX3080, TOMAHAWK DDR4, 128GB RAM, SN850-2TB, Arctic 420 AIO, EVGA 1KW PSU, all in a Fractal Torrent (solid sides) case driving a LG C1 48" OLED.

Yeah, kinda crazy. Pent up credit card I guess. At least I got it all at retail prices. (!!)

Smartly or stupidly I went with Alder Lake (to run Linux of course) with the intention of pinning the P-cores to a primary Windows VM, leaving the E-cores for housekeeping & background dockers, VMs, ZFS, etc.

I talked myself into Alder because I need the highest single-thread performance I can get - I do a lot of CAD, CAM, FEA, etc in the VM. And I haven’t run an AMD since Athlon. I’m running a similar linux-vm setup on my 8700K and it’s been pretty great for a long time. but I’m so sick of waaaiting…

Was this a mistake? Skimming the posts here at L1 are a little worrying. Can anyone point me to a guide or discussion thread that might have clues to the magic formula to get is working with minimal tears? Or we can discuss it here

(Is this a “you’re screwed until Linux kernel 18” thing? Hope to be able to work around stuff until it comes out)

Side note, the old system is on Kubuntu 21.10 but I’d like to get on a rolling release. Right now I’m thinking Manjaro/KDE Plasma on ZFS. Good or bad choice? (yes, ZFS install is a pain but I ZFS and the old system will become a server that will receive snapshots from the new system)

@wendell

[twin_savage]

Is the CAD/CAM/FEA VM going to be windows? are you remoting into the VM via the network for use or will you be at the host computer (and by extension the VM) locally and just physically plug peripherals in for the VM to use?

Not a direct answer to you question but absolute worse case scenario is you’d just have to disable the e cores in the bios to ensure the VM is running on p cores… although I like the idea of using taskset to set affinity; theoretically that should work.