Using ClockGen to change FID(Multiplier) and VID(Voltage).
There are many different versions, but I found CG-ICS950405 to be the right one.
Make sure that you never have the multiplier at 10(3200+), 11(3400+), or 12(3700+) with a voltage of only .95V. So before increasing it, set the voltage to 1.4V, and decrease it before setting the voltage to .95V.
Windows will report 800MHz, but a quick check with CPU-Z will reveal the true speed.