In an effort to provide a comprehensive look at battery life, we decided to take one of our test Macs back to Snow Leopard and test each build of OS X from 10.6.8 all the way to the current build of Mountain Lion on both an SSD and an HDD. Other readers wanted to know if there would be a significant difference in battery life if the tests were run on a solid state system drive (SSD) versus a traditional hard disk system drive (HDD).
In response to our reports, we received many questions and suggestions for further testing, with some readers telling us that they experienced a similar loss in battery life after the upgrade from 10.6 Snow Leopard to 10.7 Lion.
We were able to demonstrate that the upgrade to OS X 10.8 Mountain Lion caused a significant reduction in battery life and that Mountain Lion’s first update, 10.8.1, only partially restored the lost running time. Last month we performed a series of battery life tests on three Mac laptops: a 2011 15-inch MacBook Pro, 2012 15-inch MacBook Pro with Retina Display, and a 2011 13-inch MacBook Air. We have put those builds through the same test and the results can be found here.
Originally released in April 2005, Mac OS X 10.4 Tiger is more than a little long in the tooth at this point, especially considering the astounding success of its follow-up, Mac OS X 10.5 Leopard.Update: The final builds of 10.8.2 and 10.7.5 were released by Apple on September 19. "Of course, the transition isn?t guaranteed to be as smooth as it would be from Leopard to Snow Leopard," the report said of the Tiger to Snow Leopard upgrade, "and that?s because some older, Tiger-only third-party applications need to be upgraded to newer versions that work with Leopard or Snow Leopard."
Wired said many users upgrading from Tiger should probably consider backing up their files from Tiger and doing a clean install instead. In addition, it is possible to completely erase a hard drive and install Snow Leopard without a pre-existing operating system in place, enabling users to bypass the possible headaches of an upgrade and go with a clean install instead. Wired also confirmed that they were able to upgrade a system directly from Tiger to Snow Leopard. But here?s a tip: Apple concedes that the $29 Snow Leopard upgrade will work properly on these Tiger-equipped Macs, so you can save the extra $140." "The reasoning is that these folks never paid the $129 back in 2007 to upgrade to Leopard. "For owners of Intel-based Macs who are still using the older Tiger version of the Mac OS, Apple is officially making Snow Leopard available only in a "boxed set" that includes other software and costs $169," Mossberg said. In his review of Snow Leopard, Walt Mossberg of The Wall Street Journal, Mossberg reveals that those who have been hesitant to upgrade their Mac will be able to take advantage of Snow Leopard's bargain price, without the need to install the intermediate Leopard operating system first. Though users of older Intel-based Macs were led to believe they would have to spend $169 to upgrade from Tiger to Snow Leopard, new reports state the $29 upgrade disc will work just fine.