Quote from: kb9nate on January 17, 2014, 05:59:26 AM

I know you said you tried moving the cards around but make sure that you install each one on a 16x slot first before moving it to a 1x otherwise the driver may not install properly. Also make sure crossfire isn't enabled. You might also need to put a dummy plug on that card to simulate a monitor or even just plug a monitor into it.

I had a 6950 on a 1x slot that would only mine at 1/4 of what it normally would do on a x16 slot, as soon as I plugged the monitor in it went back up to where it should be.

I will try that once more, but I'm almost positive that I have tested this. Crossfire has been disabled from the start.
Dummy plugs aren't possible on the 280x DVI-D. Drops don't seem to happen at all on the other cards either, without a monitor hooked up.

Quote from: limbaugh on January 17, 2014, 06:15:40 AM

I have a few Win8 rigs with 7970's on a Z77 and when a card is not detected it is most likely a PCIE speed (turn it to 1x) in the bios.

I doubt it's a dummy plug. I have to use a dummy when it is detected, but I can't tweak it.

Use BAMT if you don't need Windows.

I have already tried setting the PCI-E speed to 1x and to 2x (instead of auto), but this doesn't help either. The problem isn't that they don't get detected, the problem is that the Device Manager gives error codes on the card in the 1x slot, which results in the card not functioning properly.

I prefer not to use BAMT, because I really do enjoy using Teamviewer on Windows.