The Asus K42F came with a 63Wh 6-cell battery. Though 8-cell batteries are available for the K42F, tacking on only a couple more ounces in weight. Below we ran our standard Battery Eater Pro test which loads both the CPU and GPU until the battery runs out of power. During the test,
wireless radios were enabled, audio was on, and the screen was set to always on in the power settings control panel of windows. The following benchmark is more of a worst case scenario test
setup. Since it continually taxes the graphics processor as well as the CPU,
you could argue that battery life may in fact be longer under lighter duty
workloads, like simple word processing for example.
The K42F with its Core i5 540M processor and 6-cell battery lasted only a little over an hour and a half untethered, though obviously with a stock clock speed of 2.53GHz, the processor being worked in this test is significantly more powerful than the other reference machines we've included in this chart.
In terms of actual power draw, with a power meter tapped on to the Asus K42F, we saw idle power consumption hovering around an absolutely miserly 14.5 Watts and peaking at 50.3 Watts under load. For reference, a Core 2 Duo T2600 (2.16GHz) Sony VAIO machine we have here in the lab, with a 13.3-inch display, versus the K42's 14" display, draws anywhere from 23.5 Watts at idle to 53.5 Watts under full load.
What Intel has done with respect to performance-per-watt with Arrandale, is more than evolutionary; it borders on revolutionary. That's what 32nm manufacturing processes will do for you though we suppose. We're anxious to get our hands on a few of the various thin and light notebooks that will be coming to market based on low voltage Arrandale cores. More on those other cores next.