Source:-http://www.techpowerup.com/articles/ove ... idcard/159The picture above shows the disabled HD 6950 shaders in red. When unlocked, these deactivated units become active, resulting in a substantial performance increase.
AMD has two methods of locking the shader count on all of their recent GPUs. The first one relies on fuses inside the GPU, or on the substrate - a mechanism similar to Intel's multiplier locking. It is not reversible as far as we know. The second mechanism is the one we are interested in, AMD can configure the VGA BIOS in a way that it disables extra shaders, in addition to the ones disabled via the on-die fuses. This method is mostly used to create engineering samples or reviewer cards that match the target specifications. Usually production cards come with the shader count configured in the fuses, so that it can not be changed.
Apparently currently shipping Radeon HD 6950 cards from all manufacturers - which actually are all the same card with different sticker - have their shaders locked via the BIOS method, so we can exploit it easily.
These cards ship with 2 Bios options! This means there is minimal risk, if any at all, and you get a 6970 for the price of a 6950! WOOHOO!
So, after researching this over the last week, I picked up a new HD6950 for £155 delivered! Absolute bargain! This was what the 560Ti's were coming in at, and slightly o/c'd 6870's. It also has custom cooling, which will help with the extra loads and more extreme overclocking in the future.
Delivery on the 5th of December