After some digging, I found that the performance drop is documented on Apple's support Web site--though honestly, Apple's reason for forcing a drop in processor speed doesn't make a whole lot of sense. Apple justifies the speed reduction by explaining that it "prevents the computer from shutting down if it demands more power than the A/C adapter alone can provide." But what happens when a battery is no longer able to hold a charge? Does the processor speed drop in that case as well?
We benchmarked our 2.53-Ghz MacBook Pro with 4GB of RAM using Cinebench R10's multiprocessor test, and achieved a score of 5,549 with the battery present and 3,504 with the battery removed.
Lesson learned: The battery stays in. If you're a MacBook or MacBook Pro owner, you'll get the best performance out of your system when you leave the battery in. A small extension of your battery's life span is not worth a 37 percent drop in performance.
Apple notebooks run massively slower without battery
Posted on Monday, November 24 2008 @ 21:36 CET by Thomas De Maesschalck