Targeting the mid-range, XFX's R7870 and R7850 Black Edition cards
sport increased core and memory frequencies to improve performance in
comparison to AMD's reference cards. Their custom heatsinks also
promise silent operation, but see if they make any noise in terms of
performance during games.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips