Viper Lair posted a review on the MSI RX2600XT Diamond OC Edition video card
The MSI RX2600XT Diamond OC Edition already comes OC'd out of the box, 850/1150Mhz for the core and memory respectively. Neither RivaTuner or Powerstrip allowed us to make any OCs that had a visible impact on performance. ATI Overdrive allowed a 6Mhz OC on the core and 21MHz on the memory.MSI RX2600XT Diamond OC Edition Review