can't help you with a Radeon... I've been an Nvidia guy for 3 systems. Had an AMD system with a Radeon 9600 in it, haha, that was the last time I've ahd one.
Today I have a geforce 560 ti 2gb.
Skyrim is the new world I live in, haha
good luck!
http://www.videocardbenchmark.net/high_end_gpus.html
^ thats my goto resource for gpu's