Mobile Platform Considerations

If the system being evaluated is a mobile platform, an industry-based benchmark is already available: MobileMark* 2007. The EEP 2.0 methodology is not meant to replace MobileMark* 2007, as that benchmark already conveys the relevant energy efficiency of a mobile platform, which is its battery life.

However, the EEP 2.0 methodology could be used to evaluate a mobile platform’s on-AC (plugged into the wall) energy-efficient performance. The system should be connected to an external monitor, and the system’s graphic subsystem configured to display only on the external monitor. The backlight in mobile platforms is the biggest consumer of power, and by removing it from the evaluation “equation,” a tester can get a clearer picture of the power-draw characteristics of the rest of the platform (CPU, chipset, RAM, disks, etc.). This approach will provide a better comparison between desktop and mobile platforms because monitor power is not included in the desktop calculations. Removing the LCD monitor relieves the notebook of the energy burden of its integrated display device just as the desktop measurement excludes the energy used by a display device. Alternatively, a tester could first evaluate the platform configured as described here, and then retest the system using the integrated display to understand the difference between the two configurations.

Finally, the laptop’s battery should be left in the system and should be fully charged prior to beginning the SYSmark* run, because the AC power adapters of some systems cannot handle the transient power demand spikes of the system, and the battery effectively augments the available power level to cover these spikes. Such a system will not run unless the battery is present. In addition, when charging the battery and powering the system, a laptop will draw additional power for both operations. At full charge, the only power-drawn from the wall is to power the system, and will provide a more accurate measurement.