Unless you're running 10 HDDs or something like that, the Dimension 8200 will definitely run the 6200 (and presumably the 2400pro if that's lower power). I had a pretty top of the line model- P4 2.53Ghz and 1GB of ram (which was rediculous for the time), hard drive, a couple of opticals, and it ran a 6600GT without breaking a sweat. The only cards I ever heard of it having a problem with were the 6800ULtra line; anything with lower consumption than that should be fine.