Hi. You can look busid with lspci, if your videocard is in PCI slot. I had to add BUSID too to XF86Config-4 to get X work. Eg. Output from lspci: 0000:00:0c.0 VGA compatible controller: 3Dfx Interactive, Inc. Voodoo 3 (rev 01) Now add BusID to XF86Config-4: BusID "PCI:0:0c:0" Of course, use ID of your system.