Just bought a new system (the entire thing is posted in my signature).
I bought a Sapphire Radeon X700 256mb video card with it. Just downloaded the newest Catalyst (8.4) and drivers for it.
It posts as a Radeon X550XTX for some reason. In addition, I cannot get a Windows Vista experience index score out of it. It stays at 1.0 every time I refresh the score, just as if I had never run the test.
More about :annoyance ati radeon x700 radeon x550xtx
I wanted a killer processor, so I got one instead of splitting the difference with a better video card. The X700 was the best choice for $20. I can play Oblivion on highest settings at 1024x768 with 2x AA and 8x AF. Never see frames below 15 or so in combat situations. Pretty good for $20.
I got the experience index to work.... but it still shows up as an X550XTX, which I think is weird.
Maybe I will just buy a 3870 when the funds present themselves...