The Sapphire Radeon HD 5970 OC. Yes, it is a dual-GPU, single PCB card. And it has a new naming scheme, no longer following the "X2" moniker. And yes, it is an overclocked version. The Sapphire HD 5970 OC is an absolute behemoth, from its gaming horsepower, to its size, weight, cooling technology, and price tag. It is big, it is brash, and and it is entirely unapologetic. Let's take a look at the fastest gaming card on the planet.