If you decide to start an overclocking session with the Phenom X4 9950 processor; trust me you are better off with the BE editions, and the combo of an AMD 790GX based mainboard. Key to the new 790GX feature set is AMD's Overdrive interface that allows effortless overclocking of the Phenom Black Edition processors. The significant performance increase the platform can deliver to gamers using Black Edition processors is thanks to what AMD calls Advanced Clock Calibration technology. The new B3 Phenom processors can complement the 790GX chipset's overclocking capabilities very well, and Phenom Black Edition processors running at 2.6GHz stock can be pushed to 3.0-3.2GHz and over thanks to its new Advanced Clock Calibration with merely a stock cooler.

ACC, short for Advanced Clock Calibration, was planned to enhance the overclocking potential of Phenom processors. AMD hasn't revealed exactly how the technology works, even at a recent AMD technology summit the details were not handed out. But one fact is that the Southbridge has a dedicated link to the CPU. We think it boils down to ACC's ability to keep clock frequencies in sync and stabilize inter-chip communications between the CPU, Northbridge, Southbridge and memory. Mind you that this trick only works for Phenom processors, particularly for the Black Edition processors actually.

We obviously gave it a try and were able to reach much higher clock frequencies perfectly stable on the fly.

AMD's Overdrive software overclocking the Phenom X4 towards 3100-3200 MHz fairly easily. In this review we'll consistently show you results with a tweaked environment as well. Some more Overdrive features then:

Advanced Memory control

The logical CPU cores can clock down independently depending on workload to distribute power where needed, yet saving current by powering down the others. Right, I think it's time to do some actual testing.