What I should have said is that I don't know of any Windows software that allows adjustable core voltage on the Core i CPUs. On Core 2 CPUs, there used to be a voltage request register that software could write to which would ask the CPU to change the voltage. This register has been changed so you can't do that anymore. There might be another register somewhere that you can use to control voltage but Intel says that isn't possible anymore on the Core i CPUs.