Thu, 17 Jul 2008
5:00 AM - Saving energy on your PC
I've been more energy concious lately. My home PC has an Intel Core 2 Duo 6420 which supports intel enhanced speedstep technology. This means that the CPU can slow down when it's not being used to save power.
Laptop processors have supported this feature for years, but it's starting to crop up on many desktop systems as well. If your computer was built in the last two to three years, it may have this feature. It is not found on lowend processors like the celerons or slower Pentium D chips. You can confirm the features of your processor at Intel.com. AMD has a similar feature called PowerNow on their chips.
I found that Windows XP SP2 and higher support this feature, but have it turned off. Vista is much more friendly in this regard. If you have Windows XP SP2 or SP3 installed, you can turn on this feature by doing the following. Go into Power Options in Control Panel. Select Minimal Power Management.
To verify that your computer is using this setting, make sure no programs are busy running. (CPU utilization should be zero) Now, go into Control Panel, System, and view the CPU speed. You should see two speeds if it's working. The first is the maximum speed while the second is the effective speed.
My system seems to be running at about 1.6Ghz now while idle. In MidnightBSD, it tends to run much lower than that with cpufreq + powerd enabled. Now, my system can benefit a little in Windows like it does in BSD.
Anyone that uses a laptop can tell you the difference between the system when plugged in or running on battery. One of the common savings is slowing down the processor. This does something similar, but speeds it up if you do something intensive like playing a game or compiling a program.
Every little bit helps.