7. Testing The Dell Latitude X1

Four test suites are used to benchmark mobile computer battery life and performance, BAPCo's MobileMark 2005 and SYSmark 2004 SE, FutureMark's PCMark05 and, when the computer has the appropriate graphics hardware, FutureMark's 3DMark05. When a computer achieves very low 3DMark05 scores this is noted, but the scores themselves are not reported in charts and tables.

Beyond battery life and performance, laptop displays are tested for brightness, uniformity of brightness and contrast.

For details on the tests see How We Test Laptop and Notebook Computers for Home and Office

MobileMark 2005 Battery Benchmarks

The MobileMark 2005 benchmarks test how a mobile computer does when running on battery. There are four battery life tests: office productivity, research and reading, DVD playback and wireless Web browsing. The DVD playback test is run only when the computer has a built-in DVD drive or includes a dedicated external DVD drive that is powered by the computer's battery.

Each test uses real world applications and runs from the time the computer's battery reaches full charge and the power plug is pulled until the battery is totally discharged. Test results are reported in hours and minutes. In addition, MobileMark 2005 calculates two performance values while doing the office productivity test: an overall performance score and the average response time for completion of all the tasks in the office productivity test. The overall performance score is based on average response time and is scaled against the performance of a modestly powered reference system, which received a score of 100.

MobileMark 2005 tests are run with the CPU in battery saving mode. This means that the CPU speed changes according to computing demands and, in some cases, battery charge. Though it tends to increase battery life while reducing performance, this is the preferred way to run a laptop on battery and, because this is the default setting on almost all mobile computers, it is the way most people run their laptops on internal power.

Typically, a portable computer's display uses the more battery power than any other component. For the MobileMark 2005 tests, screen brightness is set using a luminance meter to between 60 and 70 nits or candelas per square meter. This level is high enough to make a computer's display easily readable and low enough to effectively conserve battery power. A standard brightness level also assures that MobileMark 2005 test results are comparable from computer to computer.