To reach the fully stable 1170MHz core clock, I set the core voltage to 1300mv in GPU Tweak and started raising the core clock speed until my testing failed, and then backed off 10MHz. At 1170MHz, it still leaves performance on the table when compared to Sapphire Toxic edition, but it takes time and the luck of the draw to bin cards that high. Considering this card comes with a 1070MHz baseline core clock speed increase of 100MHz, or just under 10% improvement in clock speed, is not a stretch expectation. From the factory, the memory clock speed is running at 1600MHz. Boosting up the clock speed on the GDDR5 memory was accomplished using the same process as on the Tahiti core and essentially delivered an identical 100MHz boost in memory clock speed improvement for your time and effort. These are not the highest clock speeds I have seen on a Tahiti-based card, but do offer up another level of performance if you spend the time to work for it.