• PC World
• » Components

Uninterruptible power supplies offer indispensable protection: They give you time to shut down your system properly in the event of a power outage, they shield your system and peripherals from voltage surges and sags, and they provide a handy way to turn on and shut down all of your peripherals at once. That protection used to come in the form of hulking boxes that consumed lots of space under your desk, but now UPSes are slimming down and sprucing up--and remaining reasonably priced.

We looked at three units with a rated load of about 500VA (voltage-amps, a rating of power output capacity), which is a popular size for home offices equipped with a PC, a monitor, a printer, and other basic peripherals. IBM's OfficePro 500 ($169 street), MGE's Ellipse 500 ($140 street, rated at 480VA), and CyberPower's 500SL ($80 street) offer slim profiles and even some design panache. You also get software that monitors your UPS's battery level and the status of your incoming AC power. All the models did their stated job well, so we recommend the least expensive one, despite its slightly lower performance.

Power in a Small Package

When it comes to style, MGE's 9-pound Ellipse 500 stands out. Its 10-by-10-by-3-inch blue form is easy on the eyes, and it can be positioned to lie flat or on its side. Not quite as striking, but also handsome, is the dark gray, 16-pound IBM OfficePro 500, measuring about 5 by 7 by 8 inches (width by depth by height). CyberPower's 14-pound 500SL is roughly the size of a box of Kleenex, about 10 by 6 by 3, resembling a sort of surge protector on steroids. It's available in ivory or black.

The CyberPower 500SL and the IBM OfficePro 500 each have three outlets that provide surge protection, plus three that offer both surge protection and battery backup. The MGE Ellipse 500 offers two surge protection-only outlets, and four that provide battery backup as well. (The surge protection-only outlets are provided for peripherals, such as laser printers, that would draw lots of juice and severely reduce your UPS's battery life.) All three models protect against surges through phone lines. The Ellipse 500 also has a handy, rotating plug on the end of its power cord, which allows you to swivel the cord in any direction to keep it out of the way of other plugs.

The CyberPower and IBM models use a serial port for communication with your PC, while the MGE Ellipse connects to a Universal Serial Bus port (a serial port version is also available). All three units come with software that shows the UPS's status and lets you adjust shutdown levels (the percentage of remaining battery power at which your system will shut down safely) and define warning messages. The software also shuts down your system in a safe, controlled fashion in case of a power outage, allowing Windows to close all the files that it keeps open.

CyberPower's PowerPanel software is the standout among the three, both for ease of use and appearance. The program's interface looks like a rack-mount component, and provides easy access to all settings. Though not as slick looking, MGE's Solution Pak is as simple to use as the PowerPanel. However, it wouldn't allow me to set the controlled shutdown power level at less than 30 percent. (If your system poses a high load, it might need the extra time that the 30 percent would provide.)

More advanced than the other two packages, IBM's PowerAlert monitoring software offers password protection and remote-control shutdown, in addition to complete control of warnings and other settings. However, along with the advanced features comes complexity: PowerAlert's interface is a bit less intuitive than that of the other software packages.