How can I manually adjust a Core 2 Duo T5550's clock in Windows 7?

Question

In Linux there is a manual control for the CPU's clock, which allows the user to precisely specify each core's frequency. In my case the available options are "Auto", "900MHz", "1.3GHz", and "1.8GHz".

However, Windows seems to forcefully deny me manual control over my CPU's clock, effectively acting as if I was permanently using the aforementioned "Auto" option.

I have already checked the "Advanced Power Management" section and made sure that "Minimum Processor State" and "Maximum Processor State" are both set to 100 for the "High Performance" plan, yet Everest shows that even with "High Performance" mode selected, the CPU clock is not at the fixed 1.8GHz setting I am trying to configure.

I fully understand how automatically slowing the processor down while idle helps lengthen battery life, reduces energy consumption, reduces temperatures, and helps prolong the overall lifespan of the equipment, but I still want to have manual control over the CPU speed in Windows as I have in Linux.

How can I manually/forcefully control my CPU's clock in Windows, overriding the system's automatic control? I want to be able to specify any of the known available frequencies at any time, not only the maximum frequency as solutions to similar questions seem to lead to.

Additional information:

• CPU: Intel Core 2 Duo T5550 1.83GHz
• Computer model: Acer Aspire 4920
• OS: Windows 7 Ultimate 32-bit

Answer 1

You might want to try the Acer ePower Management application it has a setting for changing your CPU speed.

Answer 2

RMClock is a free Windows application which supports adjustment of the CPU frequency.

RMClock is a small GUI application designed for real-time CPU frequency, throttling, load level monitoring, and on-the-fly adjustment of the CPU performance level on supported CPU models via the processor's power management model-specific registers (MSRs). In automatic management mode it continuously monitors the CPU usage level and dynamically adjusts the CPU frequency, throttle and/or voltage level as needed, realizing the "Performance on Demand" concept.

RMClock is confirmed to work on Windows XP, Windows Vista, Windows 7.