I've always liked the Turbo series from HIS. It's not my favorite series from the company, with me personally being a larger fan of the iCooler series, but more importantly the iCooler Turbo series which carries the benefits of an upgraded cooler and benefits of that pre-overclock.
What the Turbo series offers us, though, is quick to the market pre-overclocked cards, because as just the "Turbo" series and not the "iCooler Turbo" series, the model carries with it the reference cooler which ultimately means that all HIS need to do is find a stable clock speed."
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