I installed Asus’ CPU/fan monitor on my new AMD64 system, and I discovered that the system frequently changed speeds from 3.3 GHz down to 2.2 GHz. Very frequently. In fact, it spent most of its time running at 2.2 GHz. I decided to investigate, and found the setting was in Windows 7’s power management settings.
If you have a newer AMD or Intel CPU and Windows 7, you may find its power management settings aren’t quite as aggressive as they could be.
I went into Control Panel, System and Security, Power Options, then I went to the Balanced plan and clicked Change Plan Settings. I then clicked Change Advanced Power Settings, and under Processor power management, I found a setting called Minimum Processor State. It was set to 30%. I dropped it to 1%.
The processor won’t actually throttle that low, as I found out. Its minimum speed is something just over 800 MHz. But I did find it spent a lot of its time, after that change, running at 800 MHz and revving up as demand increases. But it’s surprising what tasks the computer can complete while cruising at that lowest speed. Even when slipstreaming updates, some updates don’t require the processor to jump above 800 MHz. When doing other work, I saw clock speed jumping around between 800 MHz, 2.2 GHz, 2.6 GHz, and 3.3 GHz. It usually didn’t jump to the full 3.3 GHz for long. And when I’m just scrolling down a web page and reading it, 800 MHz is usually plenty. Sometimes more than plenty.
So I can save energy, the processor can run cooler, and the fans can run slower and quieter. There’s nothing wrong with any of that. And on a laptop computer, you’ll get more battery life.
With a desktop computer, you just get the energy savings, heat savings, quieter operation, and money savings due to a lower electric bill. How much money it will save you will definitely depend on how long the computer is able to idle at its lowest speed. But it could be along the lines of $20 per year, and perhaps more. That’s not bad for a change that costs you nothing, and I’ve yet to notice any performance slowdown.