Overclocking Pitcairn
We couldn't let this review pass without taking a peek at the overclocking potential of both cards.
First up, the Radeon HD 7850 reference card clocked up from the shipping 860/4,800MHz clocks to 1,050/5,800MHz... without adjusting any voltages.
And the HD 7870 scaled from 1,000/4,800MHz to 1,158/5,800MHz using the same procedure.
The results show that HD 7850's overclocked frequencies give little in the way of improvement for scores at both resolutions. The GPU isn't throttling at any point in the benchmark, according to GPU logging, and it's difficult to determine why it's not scaling better. We tried medium-level overclocked frequencies and they, too, also showed minor increases over default speeds. Just to be sure, we also ran Crysis 2 with the overclocked settings; the benchmark returned the same type of results.
Scaling on the HD 7870 is better, rising to levels which are practically on a par with Radeon HD 7950.
