Labs

UPS devices

We tested each UPS in two scenarios: one with the PC sitting idle, and one with it running our taxing benchmarks. Our test PC was a 2.53GHz Pentium 4 computer with a single hard disk and 512MB of RAM running Windows Vista, connected to a 20in widescreen LCD display.

We charged each UPS for a minimum of 12 hours before each test, and disabled any power management features in the UPS software to ensure that the unit didn't shut down our test PC before the battery was completely flat. We also turned off Vista's power management features so that all the PC's components would stay on.

In our idle test, we left the PC displaying the Windows desktop, then unplugged the UPS from the mains. A utility running on the PC logged the time every second until the battery failed and the PC switched off. On rebooting, we examined this log file to see how long the battery had lasted. For the intensive test we repeated this procedure, but with the PC running our taxing multi-application benchmark until it failed.