Apple Confirms Macs Not Eligible For Mountain Lion Upgrade

Apple has confirmed which Mac systems will be compatible with the fast-approaching OS X Mountain Lion upgrade, and it's bad news if you're running a MacBook dating back to before 2007 or a Mac mini from before 2009. With each iteration of OS X there's always a list of machines that have been left behind, and Mountain Lion is no different, though Apple has not given any specific indication as to why older systems don't meet the grade.

The suspicion over at Ars Technica, however, is that graphics on select 64-bit systems are what's causing the issue. According to the Golden Master seed of Mountain Lion, released earlier this week, the older machines now out of the big cat loop rely on 32-bit GPU drivers, and the new OS X version won't load them.

Apple's decision, it seems, was to leave those machines off the upgrade cycle, rather than spend the time, money and effort involved in writing replacement drivers. That means no more significant OS updates for anything other than the list of models below, though Apple is still committed to releasing security patches and other bugfixes as the need arises.

Mountain Lion will arrive in July, released through the Mac App Store as a $19.99 upgrade.