Unable to get full power limit on 7900XT

Bazzite
1

I know that this is a wide-spread problem but I was wondering if anyone has fixed this in Bazzite.

My 7900XT in Windows reports around 390ish watts. I know the Windows AMD driver is reporting total board power while LACT lets you set the power limit for the GPU core. It allows me to “set” a limit of 333W which makes sense if the total board power would be around 390ish.

Unfortunately even after setting the limit to 333W I never see more than 291W. I can also tell by the temps that it is not just a reporting error. The temps are a bit higher in Windows with the power limit maxed.

If anyone know how to fix this I would greatly appreciate it.

2

Same with the XTX model. Gaming mode I’m pegged to 350w, desktop 402w after using LACT to overclock. I can underclock using LACT and it will carry over to gaming mode.
In Windows it can hit over 450-460w. Curious if this is a Linux limitation, or if it would be worth checking another Distro.

3

https://gitlab.freedesktop.org/drm/amd/-/issues/2400

I have a 7900xtx merc and currently testing.

4

OK,
Doing some fiddling with LACT. Set to max 402w.
GPU clocks = 3307
MEM clocks = 2750
Basically a + 10%

Here is picture of wattage:

2024-10-18-144924_hyprshot
2024-10-18-144924_hyprshot1167×671 192 KB

Peaks above 500 watts. Testing done in the game Prey.

5

I set the kernel parameter amdgpu.ppfeaturemask=0xffffffffff using ostree, installed lact using the rpm package from the official github (bazzite’s in-house tools do not allow to install lact, returning an error that the technology is not implemented yet). Started the daemon with the command that lact itself gave at the first startup. I set the wattage limit to 404 watts. However, still in gamemode the wattage does not rise above 350W. Even if I start lact in gamemode after a reboot, the settings will still set the limit to 404 watts, but the actual wattage remains at 350 watts.

6

It’s a known kernel bug that sadly amd has not addressed yet.

7

Does AMD even know? Or is this bug known only to the community? :slight_smile:

8

Yes they know for going on two years come January. It’s inexcusable imo.

9

This should be fixed in 6.13

10

Hi im trying to increase the power limit for my 6900xt Navi21 gpu using Bassite 41. Ive installed LACT but changing it in LACT doesn result in a change in gamescope. Im also having trouble loading LACT from gamescope. DO i need to enable overclocking features in the Kernal?

Or is this the same issue seen with the 7900XT series gpus?

My Gigabyte Gaming oc 6900XT is running at 264w max when im sure its a 315w card and should be able to run at 340ish. I wondered if i would be better editing the VBIOS and using Red Bios editor, but not sure if that works for Navi 21 series.