Hey everyone,

 

I'm experiencing audio dropouts when passing through high quality audio over the GPU.

Running Win 10/11 (had this issue with 10, thought maybe 11 would fix it) with a GTX 1080 passed through.

4 (also tried 6) 5600X cores, 12gb ram (also tried 16), running on a dedicated VM-only NVME drive (Win10 raw, Win11 qcow2 images).

Tried i440fx-7.1, i440fx-7.2, Q35-7.2

OVMF/OVMF TPM bioses.

 

Playing back 4K HDR and passing through audio over HDMI via eARC to my receiver.

I have to pass the audio through to get DTS:X/Atmos, otherwise I'd only get raw 5.1/7.1 channels without the additional metadata required for those formats.

 

Occasionally (30sec to 5 minutes intervals) there is a cutoff in sound the lasts 0.5 - 1sec, the receiver shows no audio passing through, then everything recovers and continues fine.

MPV and VLC report no dropped frames or anything out of the ordinary.

 

I ran LatencyMon whilst playing back TrueHD content and saw this:

 

More tabs:

 

MSI enabled for the GPU. Tried all interrupt priorities

 

CPU & GPU not working hard whilst playing back that video.

Tried pinning different pairs of CPU cores to no effect.

"High performance" mode is on in Windows.

I've also tried setting Power Management mode in NVidia "Manage 3D settings" to Max performance as per recommendation from the Plex/AVS forums. I think it may have helped a little, but the dropouts are still there.

 

When playing back YouTube audio it seems to be fine-ish, but every now and again (far rarer than with high quality audio passthrough) the same brief dropouts happen.

 

I've been banging my head on the wall all weekend, thinking this was a Windows/MPV/VLC/Dolby/whatever issue.
I tried playing back the same content on my XPS 13 with no onboard GPU to help it, same software and setting setup - 0 dropouts, played back Dune Part1 4K TrueHD perfectly.

Edited July 15, 20241 yr by Mazvydas

As this is now the top Google result when searching for "Unraid DPC ISR" I thought I'd leave an update.

 

Tried what I think was everything under the sun.

Tried various different configuration options regarding core isolation and boot parameters.

Tried various VM settings in Unraid (mostly followed recommendations and suggestions on this forum).

All had 0 effect.

 

I did managed to get better latency tweaking Windows though.

This guide had the biggest positive impact, might be the solution if you've stumbled across this thread.

However ultimately this did not outright fix my audio dropout issues.

 

My final solution that fixed all my problems - deleted the Windows VM and bought an Nvidia Shield Pro 🙃