Originally Posted by Princess Garnet
It's closer to and on par with a Radeon 6950. A Radeon 6870 is more comparable to a GeForce GTX 560 (non-Ti).
HD 6870 ~ GTX 470 ~ GTX 560 Ti.
HD6950 is faster than all of the above cards, Its closer to GTX 570 performance.
It is not a very uncommon case to see a card that can't OC well. I had a similar problem when I tried a GTX 560 Ti that can't go above 900 MHz whatever VID I set it too. I thought for a second to replace my GTX 470 with it. but only 900 MHz was a big disappointment. It is even worse than my GTX 470 which is a total pos... can't even do 800 MHz. It just seems that I am unlucky when it comes to GPU OCing.