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Re: kvm win8 guest audio is terrible.





Den 31.05.2019 01:51, skrev R. Ramesh:
More info needed:

- HW (cpu, graphics, soundcard)
Motherboard audio. I think it is realtek alc 887.
So, bog standard. Should work.

- BIOS (cpu power-states)
Guest cpu? Not sure how to answer this. I did not do anything special. My command looks something like this

No, bare metal. If the box takes a nap, sound will stop. Even 1 ns might be audible.
/usr/bin/kvm -usbdevice tablet -full-screen -localtime\
?????? -vnc $vnc -k en-us \
?????? -drive file=$diskC,index=0,media=disk,cache=writeback \
?????? -vga qxl\
?????? -m 2047 -net nic,model=virtio,macaddr=$mac \
?????? -net tap,ifname=tap2,script=no\
?????? -soundhw all &
I use pass-thru hdmi, and sound on that. Works well. Can't put my finger on anything you are doing wrong. I believe vnc is more light-weight than spice, so, good I believe.


- Host setup (power states,audio setup)
Host is core-i5 cpu. Here is the first few lines of cpuinfo
processor???????????? : 0
vendor_id???????????? : GenuineIntel
cpu family?????????? : 6
model???????????????????? : 42
model name?????????? : Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
stepping?????????????? : 7
microcode???????????? : 0x18
cpu MHz???????????????? : 1651.812
cache size?????????? : 6144 KB

Should have enough oomph. Throttled to half speed I see. Might want to set policy "performance". Again, check bios settings, and also power policy in host OS.


- VM config.
I think my kvm command line answers this. If not, please let me know what you are looking for.

No further questions your honour. :-) . Can't help much I'm afraid.

If you have more than one usb-"card" on your pci-bus, you might try to pass one directly to the guest, and use an USB sound-card, to by-pass all emulation. I do that for on guest I have (XEN, not kvm). Works OK-ish. USB-chips are finicky though, so it might not work. Different PCI devices might be on single chip that don't like to run on separate vm.