We normally use Sapphire TriXX to overclock, however MSI have their own specialised overclocking tool, based on Rivatuner, called MSI Afterburner.
We managed to push the core to 1,100mhz with this tool, although the slider was limited to this point. This translates to a very healthy 25% increase on the core clock.
The memory could be increased to 1382mhz, translating to an almost 11% increase.
At the manually overclocked speeds, the MSI R7950 Twin Frozr III managed to outperform the R7970 Lightning at the ‘out of the box’ settings. 8,702 points is only around 600 points less than the GTX590!