GPU performance question

My rig with 7 GPU's is getting bad results with 1 GPU.

Claymore 11.1
Drivers: 16.10.3
7x XFX 480

ZEC - Total Speed: 1632.550 H/s, Total Shares: 17, Rejected: 0, Time: 00:03
ZEC: GPU0 266.104 H/s, GPU1 263.543 H/s, GPU2 259.511 H/s, GPU3 53.327 H/s, GPU4 263.697 H/s, GPU5 261.910 H/s, GPU6 264.395 H/s

Any suggestions?

Try the GPU by itself, try it in a different slot.

If it is still bad, try it on a standalone machine and run a graphics stress test on it. If it fails, send it back for warranty replacement.

Very strange. I have plugged the monitor cable out and run the miner with Teamviewer and the problem is solved!

ZEC - Total Speed: 1817.237 H/s, Total Shares: 110, Rejected: 0, Time: 00:02
ZEC: GPU0 259.879 H/s, GPU1 258.270 H/s, GPU2 255.182 H/s, GPU3 262.681 H/s, GPU4 259.055 H/s, GPU5 259.497 H/s, GPU6 262.612 H/s

Glad to see you figured it out! Windows should have run without a monitor, but whatever works.

Had this exact situation happen with a 3 card rig. Plugging an active monitor connection into the affected card solved the problem. Happened on windows 10 with me.