We’ve never been major advocates of GPU overclocking, as the minor gains you achieve often don’t justify the added heat and instability. But there’s a clear difference between Billy Joe doing a maximum overclock on his GPU and a vendor overclocking the part at the factory.So when XFX offered up its XXX Edition of the already-fast Radeon HD 5870, we were naturally curious. XFX pushes the HD 5870 to 875MHz (3 percent over the stock 850MHz) and juices the memory to 1,300MHz (8.3 percent over the stock 1,200MHz). At first blush, a 3 percent core overclock seems minimal. Given that the card costs about $430, versus about $405 for the stock XFX variant, is it worth the extra jingle?