I have a HD7850 on a 64bit OpenSuse 11.4. I have the newest Catalyst driver and APP SDK installed. When I use clinfo it only lists the processor.
There is an X server running but the display is connected to the integrated graphics of the Intel processor and not the HD7850. I already found  and now have only
in my xorg.conf. The PCI id is correct (confirmed with lspci) and fglrx is also loaded. According to the xorg.log it does not seem to get initialized.
The card still does not show up.
Connecting the monitor to the HD7850 and using the default settings from aticonfig --install ends up working. That's not what I want in the end though. As I said I would like use the HD7850 as a plain compute device and the integrated graphics for output to the monitor.
The problem was somewhere else. I though that I could use the integrated graphics and the GPU at the same time unfortunately the chipset does not support this.
Once I found that out I followed the instruction in this post  in combination with the knowledge base article "Application Note - Running ATI Stream Applications Remotely"  and now it even works over ssh.