Thanks Claymore
I have four cards. three card give roughly 160-180. but one card give 45 h/s. All the cards are 480 4gb and 8gb. I swipe the riser but did not help.
Any idea
Thanks,
Get GPU-Z and look at clockspeeds of cards. Sometimes a card won't properly ramp up clocks under load if there are no monitors plugged in. You can also get an HDMI display emulator off Amazon for $15.