Overclocking on ASUS HD 7970 DirectCU II was fruitful, based on the fact that this card came with standard reference clock speeds of 925MHz on the core and 1375MHz on the 3GB of GDDR5 memory. By using ASUS GPU Tweak and other tools, I was able to reach overclocks of over 22% on the core and over 20% on the memory with the final clock speeds of 1134MHz and 1669MHz on the core and memory, respectively. These are pretty significant jumps from the baseline clock speeds and offered up significant bumps in performance. Not 20%+ on average, but significant, none the less.



Link: OCC