1 more thing that HD 7770 Card Bus is PCI-E 3.0
so will there any be issue with the Card Bus ?
I am Currently using 9500GT DDR3 which is PCI-E 2.0 and it runs fine .
pci-e cards are back compatible. i have a gtx 670 which pci-e 3.0 and my board only supports 2.0. youll be fine, all graphics cards are back compatible