XFX factory overclocked the top Pitcairn Pro graphics chips and used them for its Black Edition branded Radeon 7850 cards. The 7850 reference clocks are 860MHz for GPU and 1200MHz for memory, but XFX overclocked the GPU by 115MHz and the memory by 50MHz (to 975MHz and 1250MHz respectively).
AMD Overdrive supports overclocking but AMD limited it to 1050MHz. XFX Black R7850 ran happily at this clock. The same happened with our memory overclock attempt, as AMD Overdrive had its own slider limits.
GPU temperature was great even after the overclock, only a degree or two higher than normal.
AMD power regulator does dynamic monitoring of consumption and if an app burdens the GPU’s TDP limit, the card will downclock.
Radeon HD 7850 has great power/performance ratio. We didn’t have any reference HD 7850s to compare consumption to that of XFX Black Edition Radeon 7850, but a comparison to other graphics cards reveals the quality of XFX’s design and the excellent performance at low consumption. When idle, Black Edition R7850 consumes about 10W, although ZeroCore drops this number to about 1W. ZeroCore is a new technology that will send the card into a kind of sleep mode when the computer is idle and no apps require the display. Our additional overclocking (1050MHz for the GPU and 145MHz for the memory) increased the power requirements by 10W compared to XFX’s factory clocks.