Ive got 2 old socket 775 mobos kicking around, both can be 5 card rigs with risers. Socket 775 2 and 4 core CPUs can be picked up on ebay with heatsinks for the price of afew beers. Coupled with 4 or 8gb ram and a usb flash drive, ive got 2 ready and waiting rigs.
No issues with socket 775 right?
I've ran a few 775 socket mobo rigs. Not a lot of BIOS options to get all 5 pcie slots to work with risers, so don't expect too much out of them.