PhenomMsrTweaker A utility to completely customize the Cool & Quiet feature of AMD K10 (Phenom etc.) processors. It may be used to overclock and/or undervolt the CPU. Its primary aim is to allow on-demand use of the powersaving Cool & Quiet feature even when running the CPU above its original speed.

PhenomMsrTweaker allows to fully customize two CPU performance states: multiplicator (per core), Vcore (CPU VID) and integrated Northbridge voltage (NB VID) of P-states 0 (performance) and 1 (powersaving).

Additionally, it provides a customizable replacement for the standard implementation of Cool & Quiet in the Windows driver and allows to control standard or custom Cool & Quiet via on-the-fly power scheme switching.

System requirements
* AMD K10 CPU (Phenom, Phenom II, Athlon X2 6500 and 7750...)
* Windows XP+ 32/64 bit, .NET Framework v2.0+

Some background infos
What about these P-states?
Each core of a K10 CPU may run in one of up to 5 performance states (P-states). P0 is the highest-performing (default) state, the others ascend to the max-powersaving state. Phenom CPUs use only 2 states, P0 (high performance) and P1 (powersaving). Phenom II CPUs specify 4 states, P0 to P3.

Each core boots in the P0 state. If Cool & Quiet is enabled, a driver may put a core later in a powersaving state if its load is low and then back to a higher-performing state when its load increases.

Each one of these per-core P-states consists in:
* Some background infos
* What about these P-states?
* Each core of a K10 CPU may run in one of up to 5 performance states (P-states). P0 is the highest-performing (default) state, the others ascend to the max-powersaving state. Phenom CPUs use only 2 states, P0 (high performance) and P1 (powersaving). Phenom II CPUs specify 4 states, P0 to P3.
* Each core boots in the P0 state. If Cool & Quiet is enabled, a driver may put a core later in a powersaving state if its load is low and then back to a higher-performing state when its load increases.
* Each one of these per-core P-states consists in:

PhenomMsrTweaker allows you to customize these settings for all cores and the first two P-states, P0 and P1. Therefore you may choose your optimal settings for P0 (overclocked state) and P1 (undervolted state).

PhenomMsrTweaker works just like K10Stat, but additionally provides these features:
1. Individual core multis in both P-states.
2. The 3rd core of my X4 9950 is a bottleneck. By clocking it at 2.88 GHz (11.5 * 250) while running the others at 3 GHz (12 * 250) I'm now able to use a Vcore of 1.4V instead of at least 1.425V for 4x3 GHz.
3. This might allow you to save some mV or squeeze some more MHz out of better-performing cores.
4. Cool and Quiet does not need to be enabled to apply the P-states.
5. If you only use P0, you may change the P0 settings and apply them instantly (they'll remain active until the next reboot).
6. Restriction to max. 2 P-states (P0 and P1) when applying the settings.
7. This only concerns Phenom II CPUs. I think that 2 states are enough and only P0 and P1 are customizable for now. This prevents the cores to enter not user-definable P-states (which may cause instability when overclocking the Northbridge or the HT reference clock).
8. On-the-fly switching of Windows power schemes (Vista+).
9. I encourage everyone to use power-saving techniques like Cool and Quiet to save some money and aid mother nature. Therefore I recommend enabling Cool and Quiet in the BIOS menu and controling it via power schemes (min CPU and max CPU settings). So if you are about to play a game, you may disable Cool and Quiet temporarily by switching from the "Balanced" power scheme to the "High performance" one.
10. Sadly, Vista is not able to display the power options in the systray if your system has no battery, therefore you cannot switch quickly between the power schemes. This is why you may switch it in PhenomMsrTweaker (the current P-state of the first core is indicated as well).
11. A configurable replacement for the standard Cool and Quiet implementation in the Windows driver.

The license of this software is Free, you can free download and free use this cpu benchmark software.