I have recently installed a p8z68-v pro with an intel i5 2500k, 16gb ram to go along with the ssd, 2tb HD and new case I bought. All works fine except for I cannot get the board to recognize my HD 5770 and another cheaper video card at that.
At first I thought maybe it was a power problem with the 650W not giving out enough to get truely power the card although it appears to turn on and light up. I tried another cheaper card that doesn't require a 6 pin power, I unplgged as many power things that I could besides the heatsink fans, 24 and 8 pins on board and SSD and still could not get windows to even see it in device manager. I went into the bios and seleted PCIE/PCI as the graphics adapter and updated the bios to the newest version. The HD5770 works just fine in another machine.
At this point I can only think that the board needs RMA'd but before I do that any other suggestions would be nice.