To overclock the card we used Catalyst Control Center.
We achieved fairly good overclocks on the card, with a 13% increase on the core and an 11% increase via the GDDR5 memory. This increased Far Cry 2 performance by 3 frames per second, which was noticeable. Temperatures only rose by 2c under load which is excellent and another indication that the Arctic Cooling unit is really one of the better coolers we have seen for a HD5670.