On Windows, the Wattman driver functionality allows to both in=
crease and
decrease the GPU power consumption to either 150% or 50% (100% +/- 50%).
There already is such functionality implemented on Linux for the decrease p=
art.
"cat /sys/class/drm/card0/device/hwmon/hwmon0/power1_cap" returns=
"48000000"
for my RX 560, which is the allowed maximum GPU power consumption of 48W.
I can successfully set lower values like e.g. "echo 30000000 >
/sys/class/drm/card0/device/hwmon/hwmon0/power1_cap" to set maximum GP=
U power
consumption to 30W.
However, unlike on Windows with Wattman, it's not possible that I can set
higher values than "48000000" to increase the maximum allowed pow=
er
consumption.
For instance, already "echo 49000000 >
/sys/class/drm/card0/device/hwmon/hwmon0/power1_cap", which is just 1W=
above
48W, is forbidden, it just returns "invalid value".
On Windows, Wattman allows setting GPU power consumption to 72W (150%) for =
my
RX 560.
Additionally to "/sys/class/drm/card0/device/hwmon/hwmon0/power1_cap&q=
uot;, there
also is "/sys/class/drm/card0/device/hwmon/hwmon0/power1_cap_max".
"cat /sys/class/drm/card0/device/hwmon/hwmon0/power1_cap_max" ret=
urns
"48000000" as well for my card.
However, the value has no setter:
https://cgit.freedesktop=
.org/~agd5f/linux/tree/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c?h=3Ddrm-next-=
4.18-wip#n1336
Unlike power1_cap, which has amdgpu_hwmon_set_power_cap() as a setter and t=
hus
can be adjusted by the user. So, power1_cap_max is read only.
To conclude: There is no way implemented for the user to increase the maxim=
um
allowed power consumption.
It would be nice if this would be implemented, as it basically is the only
missing piece to adjust the GPU's performance like with Wattman on Windows.=