MSI afterburner. Unlocking the bios to a 6970 is not guaranteed and in some cases the unclocked shaders are lasered off. Most games would run fine with a 6950 and flashing to a 6970 only adds a 10-15% performance boost. You can make up half of that performance just through OC'ing alone. IMO OC/flash your 6950 when you need to, when those extra fps are needed for smooth game play. otherwise, you risk bricking your card.