7900 XTX Default Power Cap lower than on Windows
Brief summary of the problem:
Reading out the power cap for the 7900 XTX gives me a value of 291 Watts:
[jaap@Jaap-Desktop ~]$ cat /sys/class/drm/card0/device/hwmon/hwmon0/power1_cap
291000000
However, from what I read online from other users and reviews, the power cap of the 7900 XTX should be 355 Watts by default, as it also has this value on Windows. Manually increasing the power cap to 350 Watt (355 Watt is currently impossible due to a bug, see: #2356) brings measurable performance improvements. That means that right now, the card is underperforming on Linux compared to Windows.
Hardware description:
- CPU: AMD 5900X
- GPU: Reference 7900 XTX bought directly from AMD
- System Memory: 2x16B + 2x8GB 3200Mhz memory, for a total of 48 GB
- Display(s): LG UltraGear 27GP850-B 165Hz + LG UltraGear 27GN850-B 144Hz
- Type of Display Connection: Both connected via Displayport
System information:
- Distro name and Version: Archlinux
- Kernel version: 6.1.10
- AMD official driver version: mesa-git 23.1.0_devel.166210.8f928a95e16.932463d268438ce945b21718552d92ab-1
How to reproduce the issue:
Simply get the current power cap via the earlier mentioned comment. Alternatively, you can also use a game to put your GPU load at 100% and observe that the power consumption of 'PPT' as reported by sensors
does not pass 291 Watts.