I have no problem at all entering the GPU DIMM Post screen with that configuration.
I notice your card is not in the First PCI ex slot. It needs to be to get full bandwidth from the CPU without the PLX chip.
Intel 3930K 5.5ghz+, DDR2600 , 3570K ,3770K
ASUS RIVE, MVG,MVF,MVE.MIVE,MIVG -EZ
G.Skill RipjawZ,PI and Trident X
ASUS 7970, GTX580,570,470,460 etc etc
Antec HCP 1200w x 2 and Coolermaster 1200w
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Proud to be an ASUS power user!!!
Could u test to plugin your card into the 2. slot... just for this test?