To overclock the DirectCU video cards, we used the Asus Smart Doctor utility. Here, we're showing the rated frequency of the cards in blue, and the overclocked speeds we reached in gold. Relatively speaking, the GTX 570 was the most impressive of the group, reaching 970 MHz from its rated speed of 742 MHz, a 31% boost. The GTX 580 increased by 28%, the HD 6950 by 25%, and the HD 6870 by 18%. Interestingly, the HD 6970 was only able to muster an 8% overclock.
We also overclocked the memory and got some pretty good results. The HD 6950 hit 1530 MHz, an increase of 22% over its rated frequency. It was followed by the GTX 570 with a 21% increase, and the 580 with a 20% bump. In addition, the HD 6870 was able to improve by 19%. Once again, the HD 6970 brings up the rear with a 19% overclock.