I am currently running windows 7 64bit with cgminer. I have a dual psu on a Gigabyte GA-990FXA-UD3 with 4 7970s. I am planning on running the mobo and 2 7970 and 1 7950 on the 1250w and 2 7970 on the 1050w. I can get 4 cards to show on the mobo but when I plug the 5th I can't get it to show for some reason. I have 2 7970 on the mobo and 2 7970 on powered x16 risers, and the 7950 on a powered x1 riser. I know the x1 riser works slot works when I only have 4 cards connected but can't get the 5th to read no matter what combo I use. Any help would be appreciated.

Is it safe to use unpowered x16 risers on 7970s? I have two sitting here unused because they won't fit on my board without risers and the only thing I have right now are unpowered.