Overclocking the Radeon HD 7970 GHz
With more aggressively binned GPUs and intelligent voltage and frequency scaling now incorporated into the Radeon HD 7970 GHz Edition, we were curious to see how much frequency headroom the card had left in the tank for overclocking. So, for our next set of performance metrics, we spent some time tweaking the GPU and memory frequencies on the new Radeon HD 7950 GHz Edition using the Overdrive utility built into AMD's Catalyst drivers.
We experimented with a couple of different settings on our card. First we simply cranked the PowerTune limit to the maximum +20 value to see if the card would maintain its boost clock for longer periods and offer better performance without actually overclocking. And secondly, we actually tweaked the GPU and Memory clocks until the card exhibited signs of instability.
With the Radeon HD 7970 GHz Edition's PowerTune limit increased, it didn't offer much additional performance. AvP reported a mild .2 FPS increase, but Metro 2033 showed no change. Overclocking the card, however, resulted in significant gains. We were able to push our particular Radeon HD 7970 GHz Edition to an 1195MHz GPU clock with 1550MHz (6.2Gbps effective) memory. We were actually able to push the card over the 1.2GHz mark, but unfortunately started to see some funky visual artifacts, even though the card didn't crash. At its overclocked speeds, the Radeon HD 7970 GHz Edition showed some nice gains and ended up posting the best scores of the bunch.