Hardware Tips: Conserve Energy With a PC Power Regimen
Save power and protect data from blackouts, USB 2.0 vs. FireWire, increase a page's printable area.Kirk Steers
Kirk Steers is a PC World contributing editor. Hardware Tips welcomes your tips and questions and pays $50 for published items.
The only place you used to have to worry about your computer's power consumption was in midflight at 35,000 feet. Today's blackouts, brownouts, and skyrocketing electricity rates have brought those concerns down to earth. Managing your desktop PC's appetite for electricity can save you money, extend the system's life, and prevent data loss.
The flow of electricity is measured in watts. Your hard drive uses between 5 and 25 watts, your CPU between 20 and 45 watts, and your 17- or 19-inch monitor from 80 to 150 watts. A well-equipped PC running at full steam will burn from 200 to 300 watts--and sometimes more.
Power-company charges are based on the number of kilowatt-hours you use. My last electricity bill charged 15 cents per kilowatt-hour, but increases are expected. (That doesn't include transmission and distribution charges and other fees and taxes, all based on usage.) My PC and monitor use about 250 watts at full bore, or almost 4 cents an hour.
Sound like small change? If your PC's turned on for an average of 40 hours a week, your PC energy bill could be about $80 a year. If you keep your PC for three years, the cost of powering it could represent 15 to 25 percent of its original price.
Most PCs now support either Advanced Power Management (APM) or the Advanced Configuration and Power Interface (ACPI). To check your PC, select Start, Settings, Control Panel, System, click the Device Manager tab, open the System devices listing, and look for entries with either 'APM' or 'ACPI' in the name. If you don't find either, power management may be disabled or not installed on your PC--and enabling it can be tricky.
APM, the older and less flexible standard, has five settings, ranging from full on to APM off (see Figure 1). Adjust the settings in either the CMOS setup program or Control Panel's Power Management utility. The settings can conflict, however, so you may have to experiment.
Open your system's CMOS setup program--typically by pressing Delete or F1 as the PC boots up--and go to the Power Management menu. If there's no menu specifically for power, look through the other menus; you're certain to find something. When you do, choose the option that enables APM.
If this causes problems, force your PC to use the earlier--and potentially more compatible--APM version 1. Go back to Device Manager and choose Advanced Power Management support under 'System devices.' Choose the Settings tab and then check Force APM 1.0 mode (see Figure 2).
If your PC is fairly recent, it may support the newer ACPI specification, which is part of the OnNow effort by Microsoft and others to make PCs easier to use and to let them boot up and shut down faster.
ACPI's Standby mode makes restarts easy, and it allows a PC to "wake up" automatically to process e-mail, modem calls, prescheduled tasks, and other external input. It improves on APM by letting you control the power consumption of individual components. At the very least, Control Panel's Power Management utility should offer power control over the hard disk and the monitor (see Figure 3).
You'll conserve the most power by setting your monitor to power down. Some 19-inch monitors devour up to 150 watts. Powering down is much better than running a screen-saver program. You'll extend your monitor's life while suppressing its voracious appetite.
When the Lights Go Out
To protect your PC's circuits from the voltage spikes that can accompany a sudden power loss, make sure that you have a high-quality surge protector installed between your PC and the wall socket. It should meet Underwriters Laboratories' UL 1449 standard, with a rated response time of no more than 1 nanosecond. A worthy candidate will cost at least $40.
For added power protection, use an uninterruptible power supply, which can provide electricity for several minutes when your wall socket suddenly runs dry. Those few minutes of power should be enough to let you save your recent work and to allow Windows to shut down properly. Some UPSs come with software that saves your work and shuts Windows down for you if the power fails while you're not around. UPSs cost as little as $100, but don't be too frugal: A device that can't meet your system's wattage needs won't be much use.
Keep in mind that a UPS has to run both your PC and your monitor. A standard PC with a 17-inch monitor can overwhelm a low-end UPS.
To determine your system's wattage requirements, add the maximum wattage rating of your PC's power supply (usually listed on the power-supply case or in your PC's documentation) to your monitor's wattage requirements (look for watt, volt-amp, or VA numbers on the back of the monitor). (Note: The monitor's voltage may be a range, as in 100V-120V, listed separately from the amperage, as in 1.6A; in this case, multiply the amps by 90.) Add 20 percent to the total as a safety factor. Don't connect any printers, scanners, or other devices to the UPS.
Compare your wattage needs with the output and running time of the UPS. The model you select should last at least 10 minutes running at the wattage requirements of your PC and monitor. One more thing to look for: UPS vendors commonly list running times at half load, so a UPS with a rated output of 300 watts will list a running time for a half load of only 150 watts.
USB 2.0 or Firewire?
I want to add a fast, easy-to-use bus to my PC so I can use an external hard drive or external CD-RW drive. I was going to add a FireWire card to my system, but I recently heard that USB 2.0 is just as fast and is currently available. Is this true? And which do you recommend?
Douglass Preston, Duluth
You're right about speed. The newest version of USB--dubbed High-Speed USB by marketers--is a little faster than the existing IEEE 1394, or FireWire, standard. USB 2.0 has a theoretical maximum throughput of 480 mbps, surpassing FireWire's 400 mbps maximum. (That's 40 times faster than current USB ports.)
USB 2.0 is an excellent way to connect hard drives, CD-RW drives, and other data-hungry peripherals, in addition to accommodating the mice, keyboards, and lesser devices served by the original USB technology. But to take advantage of USB 2.0, you need to have a working USB 2.0 port, a USB 2.0-capable operating system, and, of course, USB 2.0 devices such as hard disks and CD-RW drives.
PCs with built-in USB 2.0 ports won't be on the market until next year, but you can add a USB 2.0 adapter card to your current PC. SIIG's USB 2.0 5-Port PCI Hub is one of several PCI adapter cards that have been on sale since April. USB 2.0 hard disks are still hard to find, though they should be on store shelves in increasing numbers late this year or early next year.
The biggest question mark, however, is the availability of USB 2.0 software drivers for Windows 98, Me, and XP. Microsoft has announced that it won't issue any USB 2.0 drivers for Windows 98 or Me--leaving that to third-party developers--nor will it issue them for the initial distribution of Windows XP later this year. But Microsoft affirms its full support for the technology and says that it hopes to issue USB 2.0 drivers for Windows XP soon after that OS launches.
If you're not in a hurry to add a fast bus to your PC, wait for USB 2.0 drivers and products. All USB 2.0 devices should be backward-compatible with USB 1.1, so you can use them at slower speeds until the proper drivers appear. In the long run, you'll probably find a greater selection of hardware available for USB than for FireWire. However, many digital video cameras have standardized on FireWire. If you're into video or you can't wait for USB, FireWire is your best bet.
| Buying Information |
USB 2.0 5-Port PCI Hub Street: $60 SIIG http://www.siig.com |
Print the Unprintable
Almost every printer has an unprintable border area for each page it prints. Check your printer's manual for its minimum settings and make sure they match the settings listed in Windows under Unprintable Area.
Click Start, Settings, Printers to open the Printers dialog box. Select your printer and choose File, Properties. Click the Paper tab.
If the settings are too high, lower them to increase the printable area of each page. Be sure you don't lower them past the limits in the manual, however, or you may lose printed text or graphics.
Kirk Steers is a PC World contributing editor. Hardware Tips welcomes your tips and questions and pays $50 for published items.