There are a few utilities out there that help you undervolt your cpu. For the PC, for example, there is RMClock. For the Mac, there is Coolbook.
On the Cookbook website, however, it states that it is incompatible with OX X 10.7 Lion, and the i3/i5/i7 processors. I am interested in replicating the functionality of Coolbook, which works with OS X 10.6 Snow Leopard, and the Core 2 Duo processors, but for the newer OS and CPUs. I really have no idea where to start. As far as I know, Coolbook holds a monopoly on the Mac platform, and I was wondering if there is even a hackerish way of accomplishing the same functionality? What are some resources that you could point me to so I can begin understanding what is going on in the driver level when adjusting the voltage of a CPU?
The Problem is, i7 Cpus have no possibility to manage the voltage via software. The reason is simple. Intel has cut the external register address for voltage management, only AMD cpus has the possibility to manage voltage via software, or older core duo intel cpus. Coolbook wors but not very well on OSX Lion on older Intel CPUs, there is no update for Lion at this time. I hope that help.