This is my second rig:

TB85 Biostar MB
EVGA 1000 Gold PSU
Typical other settings/parts
Windows 10 Pro

My first rig was Sapphire 8GB cards and I got them up to 28Mh/s and 870 Watts. The problem with these XFX rx480 4gb cards is that they will not OC, will not respond to ATIWinflash or ATIflash from within Windows. I get the following message when I open ATIWinflash, "Cannot find discrete ATI video card."

I tried to force flash using ATIFlash command line. I also unlocked the cards. Both seemed to complete without error. But I can't flash the cards. I have Elipda and Hynix memory between the 6 cards if that matters. I am only getting 22Mh/s per card which obviously isn't very good.

The only thing I didn't try was using a bootable USB and flashing from there. I have a guide that describes it but I have also heard that it doesnt work so I dont want to waste my time and possibly brick them.

How can i flash these buggers?