Trouble with 2X 7970's on OpenSuse/Ubuntu
I just upgraded two GTX 580's with two HD 7970's. With the 580's, hashcat automatically recognized both cards. With the 7970's, only one device shows up when running hashcat. I am using Linux, trying both openSuse and Ubuntu with the same result. I have the most recent fglrx drivers on fresh installs of both systems. lspci tells me both cards are recognized by the system and I can also verify that each card is associated with the fglrx driver.

I am new to ati. I'm guessing I may need to redo my xorg.conf file, but I've tried with no luck. I've also read through the fourm and haven't found anything quite applicable. If I need to modify my xorg.conf file, a sample would be very helpful, as would any other advice.

aticonfig --adapter=all --initial
export DISPLAY=:0

give that a try
Brilliant!! Many thanks. Works perfectly.
probably a good idea to drop 'export DISPLAY=:0' in your ~/.bashrc or similar as well.