DFI SLI-DR help

[vforce1]

i have a DFI SLI_DR expert , a very rare board i think . im trying to use a 7970 which is working at the moment and add a 7950 to it but when i add it the system doesn't see the card can anyone tel me why?
i have  1GB ram and using windows 7 ultimate x64 using 50miner
also was using 600w psu
maybe not enough juice?


EDIT: also if i buy PCIE x1 to PCIE x16 risers will they work for a third card?

[vm1990]

i honistly have no expericance with DFI but have you tried simply adding the crossfire bridge to the cards it might be the case that both cards need to have an active display where with a crossfire bridge only 1 card needs a display (if it proves to work with the crossfire bridge then either keep them crossfired or buy a DVI dummy plug as a "fake" display for the 2nd card)

also yes many miners use PCI-e x1 to x16 raisers for there mega rigs

[vforce1]

what about power requirements?