I use TechPowerUp tool GPU-Z.exe, everything is clearly displayed, and I checked performance with 3dMark2011, was ~5400 points (original BIOS), now I have about 6050 points with second, 6970 BIOS. Card is about 12% faster, I’ve got 5-10 FPS more, it is noticeable.
And easier is change 6970...