updated 04:00 pm EST, Fri November 21, 2008
MacBook Slow WO Battery
Apple's newer MacBook range continues to exhibit an unusual design behavior that slows the system down when the battery isn't attached, testing by Gearlog confirms. Although only publicized in a support article from August that predates the late 2008 refresh, the unibody systems deliberately throttle back the processor when relying only on AC power. The company argues that the move is necessary to protect the system from an unintended shutdown if the system demands more energy than a wall outlet can provide by itself.
In benchmarking, the slowdown is also steep, dropping a CINEBENCH R10 test on a 2.53GHz MacBook Pro from 5,549 points to 3,504. The difference leaves the system at just 63 percent of its original performance.
The trait is unusual for most PC makers, which often only engage in the common practice of scaling back the processor when on battery-only power to extend runtime. It also potentially complicates the long-term use of Apple's portables by triggering a slowdown should the battery die suddenly or at the end of its practical lifetime. Users would need to either have a functioning replacement battery or obtain a new system regardless of the state of the system itself.