I am attempting to run GPU computation software on Ubuntu Server 12.04 without X since this box is going to be a dedicated computation machine. However the last requirement "Without X" is proving to be very problematic.

I have a ATI Radeon HD 5770 hooked up right now. Installed the x64 drivers from AMD's website by having it generate the correct debian packages. Ran sudo aticonfig --initial --adapter=all and rebooted. However it doesn't seem like its working

adam@adamcrunch:~$ DISPLAY=:0 fglrxinfo
Error: unable to open display (null)
adam@adamcrunch:~$ sudo aticonfig --list-adapter
* 0. 01:00.0 ATI Radeon HD 5700 Series

* - Default adapter

My software is also having issues as it just won't use the GPU for computation and tries to use the CPU.

I know during my initial install with Xubuntu that the card works and I can do GPU computation on it. However is it possible to do it on a headless server without X?

I can provide more information if needed

  • Take a look at Xvfb or something similar.
    – nsg
    Oct 4, 2012 at 13:51
  • may be env DISPLAY=:0 fglrxinfo?
    – Serge
    Oct 4, 2012 at 15:16
  • @Serge Tried that as normal user and root, same result
    – TheLQ
    Oct 4, 2012 at 15:37
  • @nsg I didn't know such things existed. I will give xvfb a try then
    – TheLQ
    Oct 4, 2012 at 15:38
  • @TheLQ Xvfb wouldn't help: that's an X server backed by memory. You need an X server that talks to the video card. There's no reason not to run an X server, even if you don't have a monitor plugged in. Oct 4, 2012 at 21:46

1 Answer 1


AMD's implementation of OpenCL requires that:

  1. An X server be running on at least one of the AMD video cards in the system.
  2. Your compute jobs must run within that X server.

If this is something you can't possibly do, then you should consider using different hardware, such as NVIDIA.

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