rather than parting out an old water cooled x58 system based around the evga x58 sli le board, i thought about keeping it and using it for a mining rig. i thought about grabbing an r9 290 to mine with, but then why waste the 3 extra pci-e slots. so mine on one r9 290 or four single slot hd 7750s. also, i understand that video memory clock speed is less important for mining so better the gddr3 7750s rather than the gddr5, right? thanks community.