Quote from: pintycar on October 12, 2012, 09:55:58 PM

Quote from: tacotime on October 12, 2012, 04:39:32 PM

The <4x PCI-e slot was a suspected issue for a long time but no one had actually verified it to my knowledge. I've only ever mined on 4x or greater slots. The transfer speed is only 500MB/s per lane with PCI-e 2.0, so it's possible that using only a single lane may cause a bottleneck.

You can verify this simply by moving around the cards. If the same cards are fine in an x16 slot but awful in an x1 slot, then you probably need the extra bandwidth.

7970 in x1 slot on an asus p8-z68 gets exactly the same hashrate as 7970 in the x16 (x8 actual rate). YMMV

this would make sense, as I can't imagine there being a whole lot of data needing to be transported between the card and the system.

however I DO wonder what the heck reaper is doing with the 2.9gb of system ram it hogs.. lol