From Fedora Project Wiki
Description
This test case test GPU switching feature in some laptops. Both Optimus (nVidia + Intel) and PowerXpress (ATI + Intel) are supported.
Setup
Enable nVidia Optimus or ATI PowerXpress in your BIOS setup.
Check if you have both graphics available: lspci | grep 'VGA'
Add the following line to /etc/fstab:
none /sys/kernel/debug debugfs defaults 0 0
Mount debugfs: mount /sys/kernel/debug
How to test
- Check which GPU you are using right now:
glxinfo | grep 'OpenGL renderer'
Usually integrated GPU (Intel) is default. - Switch to discrete graphics:
echo "DDIS" > /sys/kernel/debug/vgaswitcheroo/switch
. - Restart X. Usually logout and login back to session is enough.
- Check which GPU you are using:
glxinfo | grep 'OpenGL renderer'
It should be discrete GPU (nVidia or ATI) - Switch to integrated graphics:
echo "DIGD" > /sys/kernel/debug/vgaswitcheroo/switch
. - Restart X. Usually logout and login back to session is enough.
- Check which GPU you are using:
glxinfo | grep 'OpenGL renderer'
It should be integrated GPU (Intel).
Expected Results
- You should successfully switch between GPUs when X restarts, without freezes, graphical artefacts or etc.
- Desktop should work with both GPUs. Applications known to work in single GPU mode should work in hybrid graphics modes as well.