Just last month, Consumer Reports came up with some interesting battery test results with the latest MacBook Pro models. In the publication’s testing, the laptops’ battery life varied, sometimes lasting as long as 19.5 hours and sometimes as little as 3.75 hours. Today we learn that flawed testing, which lead to inconsistent and poor battery life on the computer was the problem. The testing used a hidden Safari developer setting which isn’t normally used by consumers. As a byproduct of the flawed testing, Apple was able to discover a rare bug in Safari. It turns out, Consumer Reports set laptop screens to a specific brightness level and then loaded a series of webpages in Safari on a loop until the battery died. Apple suggests that disabling browser caching for a test like this doesn’t reflect real-world use, but it does make sense for a synthetic test as users will continually read new pages rather than visiting the same static pages over and over again. Consumer Reports set out to make sure that the test was actually downloading data over the network rather than simply reading cached data from the disk.
Apple says it has fixed the bug in the latest macOS Sierra beta that was released to testers yesterday. The Safari fix is available to beta testers, presumably in the latest pre-release build of macOS 10.12.3, made available to registered developers on Tuesday. Apple says the full fix will be provided to the public in an upcoming macOS update. AppleInsider states:
“After we asked Consumer Reports to run the same test using normal user settings, they told us their MacBook Pro systems consistently delivered the expected battery life. We have also fixed the bug uncovered in this test. This is the best Pro notebook we’ve ever made, we respect Consumer Reports and we’re glad they decided to revisit their findings on the MacBook Pro.”