Stutter at higher refresh rates ( 75 Hz) and artifacts on desktop

Submitted by Mike Bendel

Assigned to Default DRI bug account

Link to original bug (#106446)

Description

Created attachment 139436
Xorg log

I've noticed that moving around windows and scrolling seems to stutter when running at 75 Hz on my monitor. When moving back down to 60 Hz it is completely smooth. In fact, 60 Hz looks smoother, while 75 looks like it is skipping frames.

In Windows however it is completely smooth at 75 Hz. This occurs on a Radeon Pro WX 7100.

The other thing I noticed... is that when I run at 75 Hz I get artifacts all over the desktop, which show up as flashing blue lines. This behavior is exhibited on all AMD GPUs I own (also tested with a RX Vega 64), so it's not a faulty card. I found that it is fixed by forcing the performance profile to high, like so:

echo high > /sys/class/drm/card0/device/power_dpm_force_performance_level

I attached my Xorg log. I'm running the 4.16.6 kernel. Full specs:

Threadripper 1950X
64GB RAM
WX 7100
LG 38UC99 monitor

Attachment 139436, "Xorg log":
xorg.log