Came across this thread while searching for this issue, so thought I'd register and add some info from my experience with this.
Below is a cut'n'paste of my posts from another forum.
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Basically, HDMI audio breaks for me at low load.
I have two monitors plugged in via DP, then HDMI out to an AV Amp, connected to a TV.
I only really game on the TV now and then but I use the amp for all my audio.
When the TV is off the amp just shows as a generic monitor, 1080p@60Hz.
Playing an audio file using MPC-HC, with nothing else running is really bad.
Audio distorts, crackles, cuts in and out but I noticed it improved if I started doing other things that put load on the GPU.
You can literally grab the MPC window and frantically move it around the screen and get it to put enough load on the GPU that it'll mitigate the issue.
One easy way for me to replicate this is to watch a youtube video and then minimise the browser with the video still playing.
With the browser up everything is fine, video plays with out issue, audio is perfect, MPC-HC will happily play an audio file along with it.
But a little while after minimising the browser, the audio will go to crap again.
Restoring the browser has mixed results, depending on how bad the audio got.
Sometimes a pause/play on the video will bring the audio back perfect, sometimes the audio will come back but distorted, sometimes I need to switch audio devices and back to fix it.
The above is when watching a video on youtube.
Black arrow is roughly where I hit stop. You can see the 'High priority 3D" util dop off but not completely.
Red arrow shows when the audio issues started. I'm assuming buffering of the video is why it takes a little longer for the Video Codec to catch up, finishes the buffer and then util drops to 0.
This dropping to 0 then also means the HP3D drops to 0 and one or both of these is then causing my HDMI audio issue.
Green arrow is restoring the browser window.
Blue arrow is me hitting pause/play on the video to get the audio fixed.
Have used this audio set up for years with various different PC components no issues.
Under display specs in the driver it states 'HDMI Link Status monitoring : Disabled' and does not show the current link settings/speed.
Also I have no HDMI link assurance(?) option in the drivers, I'm sure there used to be one but I've never really had a need to toggle it before.
I might see if I've got a shorter decent cable around but it means messing about moving the PC and the cable in use is only 3m, so not exactly pushing it I don't think.
I have ordered another HDMI cable just to be sure but the cable I have had been perfect on my last AMD card, a 6700XT.
The ironic thing is I was so happy to get away from the 6700 as I was always annoyed by
this old issue which I don't think ever got fixed?
So have gone from abnormally high util giving me media consumption issues to now being plagued by low util issues.
Great card otherwise though but it's gonna have to go if i can't find a fix.
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Update to the above.
New cable arrived and hasn't helped, tbh may be worse though need to test more. The impact of the issue is about the same but recovery seems worse.
Switching audio device to one of the DP monitors and then pluging headphones into the monitor also gives issues.
No where near as bad as over HDMI, audio doesn't really cut out but there are still audible issues, clicks, pops etc.
Messing about with Microsoft drivers, instead of AMD's and thought this had fixed it but it wasn't repeatable and the MS driver's give reduced functionality on HDMI audio.
Found other user reports for this on different forums but no fix found.
Not sure if this can be fixed in s/w, really hope it's not a f/w or h/w issue.
Real PITA for me at the moment. This set up worked fine with my last three GPUs.
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