Ok, so I have 5 of the above cards on windows 8.1 with CGwatcher and CGminer, but am currently only mining (or attempting to!) with 4 for the time being.
Last night it was mining for 30 minutes @ 800kHs which although not as good as I want, it was something, then I rebooted to make move it and now nothing.
Today I can't even get it to mine, it just crashes a few seconds after it starts mining, any help is greatly appreaciated!
Can you post more specs of your rig, and what your setup is?(how your powering, risers, is one card on board?)
And that motherboard can be a pain to say the least. Just set up two rigs with motherboard, was not as smooth as other motherboards I had used.