Being a "Black Edition" processor gives you a little more flexibility with overclocking because of the unlocked multiplier. To begin I started by raising the multiplier 1x at a time until the system became unstable. I was able to boot at 16x but I could not complete a benchmark, so I backed the multiplier down a half to 15.5x and I was able to complete several test benchmarks with no problem. Next I raised the bus speed 5MHz at a time, but once I tried 210MHz there was no joy. I backed off slowly, 1MHz at a time until I was able to boot at 205Mhz. During the overclocking session I did have to raise the CPU voltage to 1.5v, however CPU-Z reported it as 1.520v. So for the overclocking results we will be running at 3.177GHz (205Mhz x 15.5) at 1.5 volts.

http://www.overclockersclub.com/reviews/athlon7750/