AMD launched two new performance graphics cards in the HD 6900 series just recently. Little brother Radeon HD 6950 offers a good punch for the money. It seems it has more advantages than we could anticipate, it is namely extremely easy to transform the card to the considerably more powerful Radeon HD 6970.
AMD builds the two performance cards on the exact same graphics circuit. Cayman XT and Cayman Pro are physically identical and the only thing separating the two current Radeon HD 6900 cards is the BIOS. In other words, AMD has turned off two SIMD units with its Radeon HD 6950 BIOS. This can be reverted through a simple BIOS update.
At Techpowerup they’ve posted a guide on how to quickly and simply unlock your Radeon HD 6950 by equipping it with a Radeon HD 6970 BIOS. This has been made even easier by AMD since it decided to use dual BIOS circuits. If the update fails you can just switch to the secondary BIOS and reset the faulty update.
From 1408 to 1536 stream processors through a simple BIOS update
According to Techpowerup and its readers they have tested the unlock with 9 different Radeon HD 6950 cards and all have worked flawlessly when upgraded to Radeon HD 6970. Since then it has turned up that a few cards got aftefacts in Windows and the power management didn’t work properly but these things can be adjusted, at least the latter in most cases.
OBS! AMD may very well change this locking technology to a hardware based solution in the future, which makes this update fruitless, but the cards available today should be upgradable.