Apple Statement on Consumer Reports’ MacBook Pro Battery Testing

From a statement Apple sent to TechCrunch:

We appreciate the opportunity to work with Consumer Reports over the holidays to understand their battery test results. We learned that when testing battery life on Mac notebooks, Consumer Reports uses a hidden Safari setting for developing web sites which turns off the browser cache. This is not a setting used by customers and does not reflect real-world usage. Their use of this developer setting also triggered an obscure and intermittent bug reloading icons which created inconsistent results in their lab. 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.

So there’s a bug in Safari when you disable the cache (Develop: Disable Caches — and the entire Develop menu is off by default). Disabling the cache should decrease battery life in a test like CR’s. And if there’s a bug, I can see why it might dramatically decrease battery life. But that still doesn’t explain how Consumer Reports’s testing showed results ranging from 3.75 hours (poor) to 19.5 hours (seemingly too good to be true).

I still think something was/is wrong with Consumer Reports’s testing (19.5 hours?) but I don’t think it’s fair to say that disabling the caches is unfair or a flawed method. And while the preference setting is obscure, I wouldn’t call it “hidden”. To me, hidden preferences are the ones you can only enable from calls to defaults in Terminal. You can turn the Develop menu on by clicking a visible checkbox in the “Advanced” tab of Safari’s preferences.

★ Tuesday, 10 January 2017