====== Ubuntu - GPU - Specify which GPU should take priority ======

GPU-intensive applications should be rendered on the more powerful discrete card.

If more than one GPU is install, you can specify which one should be used.

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===== Get the list of GPU drivers =====

See [[Ubuntu:GPU:Check the list of attached graphic drivers|Check the list of attached graphic drivers]]


Let's assume you receive this result:

<code bash>
xrandr --listproviders

Providers: number : 2
Provider 0: id: 0x7d cap: 0xb, Source Output, Sink Output, Sink Offload crtcs: 3 outputs: 4 associated providers: 1 name:Intel
Provider 1: id: 0x56 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 6 outputs: 1 associated providers: 1 name:radeon
</code>

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===== Change using the name =====

<code bash>
xrandr --setprovideroffloadsink radeon Intel
</code>

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===== Change using the Provider Index =====

<code bash>
xrandr --setprovideroffloadsink 1 0
</code>

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===== Usage =====

Use a specific card for the applications that need it the most, such as games.

To select the card with Provider 1, prepend **DRI_PRIME=1**:

<code bash>
DRI_PRIME=1 glxinfo | grep "OpenGL renderer"
</code>

returns

<code bash>
OpenGL renderer string: Gallium 0.4 on AMD TURKS
</code>


<WRAP info>
**NOTE:**  Other applications will still use the default first card.  

These settings are also lost once the X server restarts.  You may want to make a script and auto-run it at the startup of your desktop environment (alternatively, put it in /etc/X11/xinit/xinitrc.d/).

This may reduce your battery life and increase heat though. 

</WRAP>

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===== References =====

https://wiki.archlinux.org/index.php/PRIME