Thread: Reduce Your PC's Power and Operating Costs

AS ENERGY COSTS rise, PC power conserva¬tion can trim from your total electric bill each year. That's enough for a nice dinner with your spouse-or if you're not the romantic type, it can get you a few months closer to purchasing a new, faster (and more energy-efficient) system.

Fortunately, you can apply changes to several configuration settings to bring the power consumption and operating costs of any system down significantly.
Save as Your PC Sleeps MODERN pcs INCORPORATE a power¬management standard called the Advanced Configuration and Power Interface (ACPI), which allows the oper¬ating system, BIOS, and hardware to co¬operate in reducing power consumption. ACPI defines several global power and sleeping states; the chart on the next page lists the relevant ACPI states and corresponding Windows XP /Vista modes, along with the power used by each mode on the example system.



You've probably put your laptop into hibernation or sleep hundreds of times, but people typically ignore these fea¬tures on desktops. As the chart shows, power use in the 53 state (Standby in XP, and Sleep in Vista) is nearly equal to that used when the PC is powered off. The 53 state drops PC power down to 10 watts or less when idle even if the system consumes considerably more power than average while active. Unfor¬tunately, most PCs I encounter are not configured to use this mode. Some older boards and peripherals may not play nice with 53, sound cards being particularly troublesome.

To tweak power management settings in Windows XP and Vista, open the Power Options applet in Control Panel. The three preset schemes are:

•Turn off monitor and/or hard
disks only

•Standby/Sleep mode

•Hibernate mode

While Hibernate mode uses the least amount of power, it takes the longest time to suspend and resume, which involves writing and reading the entire contents of RAM to and from the hard disk (using a file named hiberfil.sys). The more RAM you have, the longer the process takes. On the other hand, the Standby/Sleep mode (53) uses only slightly more power than Hiber¬nate does, yet its suspend and resume times are virtually instantaneous no matter how much RAM is installed.

A BIOS setting called ACPI Suspend Type, ACPI Suspend State, or some¬thing similar controls which sleep state (Sl or S3) Windows uses. Many systems are set to Sl by default, which keeps the CPU and RAM powered. Enter your BIOS, navigate to the Power Management menu, and change the ACPI Suspend setting to S3, which cuts power to the CPU and RAM. Enable any settings labeled 'USB KB Wake-Up From S3' (the wording var¬ies), and set the Power On Function to Any Key to let the keyboard and mouse wake the PC from standby.