not necessarily. semprons are slower cores, but sometimes clock higher. it depends on which one, and for what interface you get it for. personally i would rather an athlon XP at 2ghz than a sempron at 2.2ghz. then again, sempron's will be compatible with pci-e and such, but theyre mostly the new aged (now 64-bit) budget processors... mostly for managed computers in a network, or a home computer that's not used for gaming.
btw nice pic, haha ATI the way its meant to be played. i like both brands