I'm thinking of building my own computer. (Which I have never done before.) I had most of my components all selected, and then came the video card. I had heard that the best idea for budget systems, (I'm looking for a build around $1200 [$100 up or down]) is to use 2 moderately good video cards instead of 1 amazing card. I decided on 2 Nvidia GeForce 8600 GTS cards, as they would only total $200. But I recently learned that you need a special motherboard to run multiple Nvidia cards. I would really like to know everything you can tell me about SLI. Also, does ATI's crossfire supported cards require special motherboards? My biggest questions: Is an SLI motherboard upgradable? If so, only to Nvidia cards? If not, to I have to buy A completely new motherboard? Maybe it would help to list the components I have selected for my computer. Intel Core 2 Quad processor Q6600 Intel Motherboard D975XBX2 (I think I can upgrade it to Core 2 quad extreme later) Nvidia GeForce 8600 GTS 256mb DDR3 (Hopefully 2) 700w power supply Sunbeam Transformer Case - Black/Green CD/DVD dual layer combo drive 3gb of DDR2 RAM 320GB Hard Drive 7200RPM Windows Vista Home Premium If ATI Radeon doesn't require a specific motherboard, which 2 could I use with my system? (Closest to the 8600GTS.) And again, I need all the information I can get on both Crossfire and SLI. Thanks in advance.