as above said its really just a hd video card. not really gaming hardcore grade.
if you want gaming grade you gonna wanna look at the ati xx50 or above
xx being 48/56/57/58/67/68/69... amd so on the second half of the number will give an impression of the gaming performance 50 and up is pretty much gaming performance. 40 and below are video cards.
this is just a rough guide... also with amd cards if you looking to play games you want ddr5 ram and depending on the monitor you have you can set the amount.
anything under 16x10 you can get away with 512mb, 19x12 look at a minimum of 1gig (20+ x 16+) look at 1.5gigs and up
these are just rough estimates to help you narrow down your choices...
personally if i were you and had a limited budget i would look at a 4850 they can still be gotten really cheap... that gfx card will max out a lot of games at modest resilutions.