How to control the processor frequency of i5 in Windows 7?

Solution 1:

Go to Control Panel -> Power Options and select Power saver

That should limit the processor to a set of lower powered CPU speeds.

Of course you can always adjust the settings of the Power saver plan to only ever use the minimal state by selecting Edit Plan Settings then Change advanced power settings. On the window that opens look for Processor power management and set the Maximum processor state to 5% or something low.

On a laptop you should be able to get to the power options quickly by right clicking the battery icon in the bottom left of the task bar.

Solution 2:

I used to control CPU frequency settings in W7 using ASUS AI Suite, since I had ASUS mobo. Look for similar software on the official site of your mobo manufacturer. This tool allowed either to change frequency or multiplier.

Besides, all new Intel Core i5 processors support Turbo Boost Technology, which dynamically increases the processor's frequency as needed by taking advantage of thermal and power headroom to give you a burst of speed when you need it, and increased energy efficiency when you don’t.

Turbo Boost settings are controlled from within the BIOS. Intel® Turbo Boost Technology is a processor technology and is operating system agnostic.

Here you can read FAQ on this technology on Intel site.

Here are specs for 3rd generation of Core i5 CPU with Turbo Boost Tech.