7800gtx is crazy fast so I only need one. Plus with them being new the prices are still a bit high. If I decide I need another it prolly wont be for a year or so and I can save a lot of money buying it then. But from all the reviews I've read I doubt I will need more than 1. The 7800gtx outpreformes 2 6800 Ultras in most scenerios.

I use the raptor for my operating system and programs and use the hitachi just for storage so it doesn't slow my system down at all. Plus the hitachi is SATA 3.0Gb/s with NCQ and some tests showed that it may actually be faster than the raptor.