We take a Radeon HD 7950 overclock it the normal way and then voltage tweaked. So that way we will demonstrate not one, but two maximum overclock conditions alongside TDP, heat, noise and performance levels.
You will notice that if you go for long lifespan a long-lived card that overclocking the old fashioned way will not disappoint. A good GHz on the GPU (default = 800 MHz) is certainly something you can achieve. However voltage tweaking will bring you towards another level alright, roughly 1150 MHz.