I recently set up a PCI passthrough VM on Debian using Virtual Machine Manager to run Windows 10 for a few games. Everything seems to be running flawlessly except for my audio, which is giving me issues. Using ich6/ich9 there's pretty bad crackling and with AC97 it lags the VM like crazy and still crackles. I've followed the troubleshooting guide on the Arch Wiki, tried adjusting the bit-rate in Windows, as well as try the methods on this guy's site, however nothing seems to get rid of it. I'm using an external USB DAC (a Fiio E07K) and I'd like to avoid simply passing its USB bus through or buying a separate sound card if possible. Is there anything else I can try? Thanks!
My specs:
OS: Debian unstable x86-64
Kernel: 4.9.0-3-amd64
CPU: Intel Core i7 7700K
Motherboard: Z270X-Gaming K7
GPU1: Intel HD 630
GPU2: NVidia GeForce GTX 980 Ti
EDIT:
I managed to figure out the issue. It turns out it was an issue with my CPU layout and the host OS needed an extra core for audio emulation.