A very recent Engadget post says that you can turn your AMD Radeon HD 6950 graphics card to a higher 6970 model using just a BIOS flash. This may void the warranty, probably, but you get all the extra power at absolutely no cost whatsoever. Choose wisely!
very recently, and it appears that the lower model is actually the same as the higher one, but its capabilities are capped by some firmware settings. Those guys at techPowerUp found out how to hack the 6950 to actually, literally turn it into a 6970.
The full guide on how to do it is mentioned in the Engadget post but not linked to. Here it is! You can do it on your own too.
[techPowerUp via Engadget]