====== Ubuntu - GPU - AMD GPU - Monitor - Manually - Check the DRM card number the GPU ======

**DRM** (Direct Rendering Manager) is a subsystem of the Linux kernel responsible for interfacing with GPUs of modern video cards.

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<code bash>
ls /sys/class/drm/ -l
</code>

returns:

<code bash>
lrwxrwxrwx 1 root root    0 Jun  7 23:08 card0 -> ../../devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/drm/card0
lrwxrwxrwx 1 root root    0 Jun  7 23:08 card0-DP-1 -> ../../devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/drm/card0/card0-DP-1
lrwxrwxrwx 1 root root    0 Jun  7 23:08 card0-DP-2 -> ../../devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/drm/card0/card0-DP-2
lrwxrwxrwx 1 root root    0 Jun  7 23:08 card0-HDMI-A-1 -> ../../devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/drm/card0/card0-HDMI-A-1
lrwxrwxrwx 1 root root    0 Jun  7 23:08 card0-HDMI-A-2 -> ../../devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/drm/card0/card0-HDMI-A-2
lrwxrwxrwx 1 root root    0 Jun  7 23:08 renderD128 -> ../../devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/drm/renderD128
-r--r--r-- 1 root root 4.0K Jun  7 23:08 version
</code>

<WRAP info>
**NOTE:** This shows that there is only a single card, i.e. **card0**.
</WRAP>

<WRAP important>
**NOTE:** Paths like **/sys/class/drm/...** are just symlinks and may change between reboots.

  * Persistent locations can be found in **/sys/devices/**.
    * e.g. /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/. 

Adjust the commands accordingly for a reliable result.

</WRAP>



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===== References =====

https://dri.freedesktop.org/wiki/DRM/