RX 480 sclk clock speed lowers when under load
Submitted by Christoph Haag @ChristophHaag
Assigned to Default DRI bug account
Description
Created attachment 129917
screenshot with echo manual > power_dpm_force_performance_level
My GPU is the factory overclocked XFX Radeon RX 480 XXX OC, this might have something to do with it.
I noticed this on agd5d/drm-next-4.12-wip and found similar behavior on 4.10, 4.9 and 4.8.
It's even affected even with echo manual > /sys/class/drm/card0/device/power_dpm_force_performance_level
I've made a screenshot of radeon-profile on linux 4.8.14 and annotated it.
Steps I took:
echo manual > /sys/class/drm/card0/device/power_dpm_force_performance_level
echo 7 > /sys/class/drm/card0/device/pp_dpm_sclk
then started unigine-heaven, closed it, waited a couple of seconds, started furmark, closed it, waited a couple of seconds and then ran another echo 7 > /sys/class/drm/card0/device/pp_dpm_sclk
When the GPU is "relatively" idle (just displaying the desktop with a browser, etc.) this doesn't happen. I can echo any number in /sys/class/drm/card0/device/pp_dpm_sclk and it sticks.
But when I start applications that put some stress on the GPU, the sclk clock lowers - and stays on a lower level even when the load is gone, until another number is echo'ed into /sys/class/drm/card0/device/pp_dpm_sclk
Attachment 129917, "screenshot with echo manual > power_dpm_force_performance_level":
