Windows 11 Guest VM bad audio.

[tomt]

Hi

I'm running VirtualBox Version 6.1.32 r149290 (Qt5.6.2) with a Windows 11 Guest virtual machine.
As far as I can tell everything seems to be working, but I get really bad audio.

Watching a YouTube video the audio is really stuttering, almost sounds like its underwater.
Has anyone else had this issue and can it be fixed ?
I've tried a Win 10 virtual machine and the audio has issues but not as bad as Win 11.

The PC this is running on is a Win 10 Pro, AMD 3600, 16GB Ram and TPM is on.
I get no audio or video issues on the PC, only on the virtual machine.

Thanks

[scottgus1]

Start the VM from full normal shutdown, not save-state. Run until you see the problem happen, then shut down the VM from within the VM's OS if possible. If not possible, close the Virtualbox window for the VM with the Power Off option set.

Right-click the VM in the main Virtualbox window's VM list, choose Show Log. Save the far left tab's log, zip it, and post the zip file, using the forum's Upload Attachment tab.

[tomt]

Hi

Thanks for the reply.
I compared the Windows 10 and 11 settings within VirtualBox and found Windows 10 had System / Acceleration / Paravirtualization Interface set to Legacy, but Windows 11 was set to Hyper-V.

I stopped the Win11 VM and changed this setting to match Win10 and now it seems to be working fine.

Thanks

[scottgus1]

Windows 10 had System / Acceleration / Paravirtualization Interface set to Legacy

Yep, that's a good catch!

Glad you're up and running.

[mpack]

That's probably just a hack, not addressing the real issue, which hence may return.

Enabling the hypervisor API allows the guest OS to make more efficient use of CPU, which probably reduces the CPU overhead that leads to the scratchy audio. But it also indicates that CPU allocation was poor to begin with - probably giving too many or too few cores to the VM. 2 cores is usually best.

Also, reducing audio expectations can help too. E.g. if you don't real 7.1 HD audio inside the VM then don't enable it: stick to stereo if you can find the setting.