My mobo is an Asus P6T Deluxe V2.  I'm sure it can run 2 cards at x16.  I'm on Windows 7.  I plan to continue using the GTX 260 for normal stuff.  I was going to use the HD5830 as a dedicated miner 24/7 because I leave my computer on all the time anyway.  So, would I be better off selling the GTX 260, and getting a couple of 5830s?  Or even a 5830 and something less powerful, seeing as I don't game much anymore?