Arch Linux

v2vm

Member

Registered: 2018-03-03

Posts: 20

Sound was slowed down via DisplayPort on AMD R9 280x Graphics Card

Hi guys,

My AMD R9 280x graphics card, when connected to a 4K monitor via DisplayPort, slows down audio, or does not play audio at all.

If I switch to a VEGA 56 instead, this issue goes away.

Symptoms
1. Sound in youbube and mpv (when playing local movies) were "slowed down", with lower-than-normal frequency, as if it were in slow motion, however, the audio and video were in sync.

2. When playing spotify or mpv / kodi, there was no sound at all; sometimes youtube also randomly had no sound

3. This only happened when output went through the 280x's DisplayPort connected to a 4K monitor's DisplayPort;
    When I selected motherboard's audio out as the output, the sound was perfectly normal.

4. Other non-audio graphics appears to be normal and I'm sure it's running at 60HZ.

Research done
This issue was very similar to or exactly the same as the one from this old topic: https://bbs.archlinux.org/viewtopic.php?id=209385
But in that thread, there was no solution.

Hardware info
Motherboard: ASUS x570 TUF, upgraded to BIOS v1404 (v1405 is out but I cannot boot)
CPU: AMD Ryzen 3700x
GPU: PowerColor AMD R9 280x
RAM: XPG 16gb (2x8GB) AX4U360038G17-DT41

Software
Arch was freshly installed in October 2019 and has been upgraded to latest (as of Dec 3, 2019).
I remember it was fine at the time, but now I'm not so sure, because this is a work PC so I rarely play any video/audio, I only noticed it until recently.
I'm running xfce DE with x11.

Troubleshooting done
1. Tried Firefox and Chromium, same problem;

2. Tried mpv / kodi / spotify to play local videos and audios, same problem;

For the above 2 steps, the videos being played were not stressful, 4k/1080p/720p all had the same problem.

3. My RAM has its clock tightened to C14, although I'd done days of stress testing CPU&RAM without issue before installing Arch, just to be sure, I restored to default RAM settings, same problem;

4. Tried upgrading BIOS from v1203 to v1404, with default settings, same problem;

5. Tried latest linux-lts, linux, linux-zen, linux-firmware and versions going back to late September / early October, same problem;

6. Tried endevourOS live IOS 20191015 (kernel 5.x), same problem;

7. Tried Ubuntu 18.04.3 live ISO (default kernel 5.x), same problem;

8. Because 280x is Sea Island, I tried Arch Wiki's section on "Enabling Sea Island Support":
https://wiki.archlinux.org/index.php/AM … K)_support

Specifically, I put

MODULES=(amdgpu) in /etc/mkinitcpio.conf and regenerated initramfs:

# mkinitcpio -p linux linux-lts

Also added radeon.cik_support=0 amdgpu.cik_support=1 to grub kernel parameter, and rebooted, same problem;

9. The card was an used item, so I wasn't sure if the original owner had modded it, so I flashed original BIOS, same problem.

Isolating R9 280x
1. Tried connecting another PC (intel iGPU) to the monitor, and all is good; So, monitor and cable were fine;

2. Took out R9 280x and put in VEGA 56, and all is good; so all other components were fine.

However, R9 280x does support 4k@60Hz:
    a. https://en.wikipedia.org/wiki/Radeon_Rx_200_series
    b. xfce reports so:  https://imgur.com/EW1mYfE
    c. by xrandr:

$ xrandr
Screen 0: minimum 320 x 200, current 3840 x 2160, maximum 16384 x 16384
DP-1 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 708mm x 399mm
   3840x2160     60.00*+  30.00  
   2560x1440     59.95  
   1920x1080     60.00    50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1680x1050     59.95  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1280x800      59.81  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    60.00  
   832x624       74.55  
   800x600       75.00    60.32  
   720x576       50.00  
   720x576i      50.00  
   720x480       60.00    59.94  
   720x480i      60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08  
HDMI-1 disconnected (normal left inverted right x axis y axis)
DVI-I-1 disconnected (normal left inverted right x axis y axis)
DVI-D-1 disconnected (normal left inverted right x axis y axis)

What else could I try to isolate and solve the problem?

Thank you very much!

Last edited by v2vm (2019-12-04 01:07:29)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,234

Re: Sound was slowed down via DisplayPort on AMD R9 280x Graphics Card

Set the power profile to high https://wiki.archlinux.org/index.php/AM … nstability and/or disable all usual runtime power management facilities:

amdgpu.dpm=0 amdgpu.aspm=0 amdgpu.runpm=0 amdgpu.bapm=0

v2vm

Member

Registered: 2018-03-03

Posts: 20

Re: Sound was slowed down via DisplayPort on AMD R9 280x Graphics Card

Thanks!

I tried:
amdgpu.dpm=0 amdgpu.aspm=0 amdgpu.runpm=0 amdgpu.bapm=0
radeon.cik_support=0 radeon.si_support=0 amdgpu.cik_support=1 amdgpu.si_support=1 amdgpu.dpm=1 amdgpu.dc=1 amdgpu.dpm=0 amdgpu.aspm=0 amdgpu.runpm=0 amdgpu.bapm=0
radeon.cik_support=0 radeon.si_support=0 amdgpu.cik_support=1 amdgpu.si_support=1 amdgpu.dpm=1 amdgpu.dc=1
radeon.cik_support=0 radeon.si_support=0 amdgpu.cik_support=1 amdgpu.si_support=1 amdgpu.dpm=0 amdgpu.dc=1
radeon.cik_support=0 radeon.si_support=0 amdgpu.cik_support=1 amdgpu.si_support=1 amdgpu.dpm=0 amdgpu.dc=0
radeon.cik_support=0 radeon.si_support=0 amdgpu.cik_support=1 amdgpu.si_support=1

And neither worked.

But your post led me to bugzilla, and I found several very similar bug reports (some dated back to 2012):
HDMI audio played back at a wrong rate: https://bugs.freedesktop.org/show_bug.cgi?id=46713
No HDMI Audio on RS880 [Radeon HD 4290]: https://bugs.freedesktop.org/show_bug.cgi?id=70880
HD Audio with 44.1 khz not working when refreshrate > 30hz: https://bugs.freedesktop.org/show_bug.cgi?id=75038

I'll wait for another motherboard, CPU and monitor to arrive to do more swapping, if it's still 280x I'll submit a bug report to bugzilla.

I'd also like to add that this 280x works well with a 1080p HDMI monitor. It so far only has this problem on a 4K DP monitor.

Last edited by v2vm (2019-12-04 20:33:06)