OS X El Capitan will run on almost 90% of all current Macs, even though it's very unlikely that the just-unveiled operating system will ever boast such a high adoption rate.
And in a departure from past practice, Apple on Monday said that iOS 9 will run on all the devices able to run 2014's iOS 8, meaning that a larger chunk of the iPhones, iPads and iPod Touches now in use should be able to upgrade this fall than in years past.
The estimate for eligible Macs was 10 percentage points higher than last year for Yosemite, a reflection of the features pause that Apple instituted for OS X 10.11, named El Capitan (El Cap) during the WWDC keynote address Monday.
El Cap will run on the same Macs as now run 2014's Yosemite, 2013's Mavericks, 2012's Mountain Lion and 2011's Lion, according to reports of the newest OS X's system requirements, which have been confirmed by Computerworld with developers, who asked for anonymity.
OS X 10.11 will run on iMacs from the mid-2007 model on; on 13-in. MacBooks from late 2008 (aluminum case) and early 2009 (plastic case) forward; MacBook Pro notebooks from mid-2009 and later (13-in.) and late-2007 and after (15-in., discontinued 17-in.) and on; MacBook Air laptops from late 2008 and later; Mac Mini desktops from mid 2009 and after; and the much beefier Mac Pro desktops from early 2008 and forward.
With some minor exceptions -- Mac Minis between mid-2008 and mid-2009, and 2007-era iMacs with only 1GB of RAM -- those requirements are identical to the ones for both Yosemite and its two immediate predecessors, Mavericks and Mountain Lion. Virtually all of those same Macs also fit the prerequisites for the even-older OS X Lion.
Together, Lion, Mountain Lion, Mavericks and Yosemite powered 89.7% of all Macs in May, according to analytics company Net Applications' tracking. Net Applications measures operating system user share by capturing the "agent string" of the browsers that visit its customers' websites. The agent string includes the operating system and its version number.
If the exceptions to El Capitan's list -- machines running Snow Leopard and Leopard -- sustain their year-long average losses through September, the month before El Cap is expected to launch, the able-to-run-10.11 Macs will have increased to approximately 94%.
But high able-to-upgrade percentages don't automatically translate into actual upgrades: It's very unlikely El Cap will be adopted by 90% of all Mac owners in its one-year lifespan as the latest.
Mavericks, the first free OS X, peaked at 64%; Yosemite, the second, is on pace to beat that by just a point or two. Some Mac owners decline the free deal, and ignore the operating system's nagging them with reminders to upgrade. Last month, for instance, about a fifth of all Macs were still running 2013's Mavericks, even though the systems were also eligible for Yosemite.
Mac owners can determine the age of their machine by selecting "About This Mac" from the Apple menu at the far left of the menu bar, then choosing "More Info..." from the ensuing window for Mavericks and earlier. The Mac's age will appear under the name of the model, as something like "Retina, 15-inch, Mid 2014" for a recent MacBook Pro notebook. In Yosemite, that information appears in the pop-up itself.
Apple is not alone in making older system requirements toe the line of a new OS: Microsoft has done the same with its impending Windows 10, which will release in late July. Most machines running Windows 7, a 2009 OS, and all of those running Windows 8 or Windows 8.1, will be able to run Windows 10.
That does not mean, of course, that either OS X El Capitan or Windows 10 will run competently on the very oldest Macs or PCs. The usual rules apply: The less memory, the slower the processor and graphics chipsets, the poorer the experience will be.
And both operating systems include features that not all the machines able to run the code can support. "Not all features are available on all devices," Apple said in the fine print in its El Cap marketing materials; those features were not called out, however.
Also staying stable this year are the requirements for iOS 9. Rather than do the usual -- drop the oldest still-supported devices from the next edition's list -- Apple said that the same devices that ran 2014's iOS 8 will be able to handle its successor.
"We want everyone to get iOS 9," said Craig Federighi, the chief of Apple's OS X and iOS development, during the WWDC keynote on Monday in explaining the change.
iOS 9 will be supported on the iPhone 4S, 5, 5S, 5C, 6 and 6 Plus; on the iPad 2, third- and fourth-generation iPad, iPad Air, iPad Air 2, iPad Mini, iPad Mini 2, and iPad Mini 3; and the fifth-generation iPod Touch.
The list goes back three years for the iPhone and iPad -- the year when Apple started selling the iPhone 4S and the iPad 2 -- and according to Apple, encompasses 83% of all iPhones, the percentage now running iOS 8.
Third-party metrics vendors have iOS 8 at an even higher share: Mixpanel, for instance, said iOS now accounts for 87% of the Apple devices that run apps with its analytics package embedded. Meanwhile, rival Fiksu put the percentage of current iPhones from the 4S on -- those able to upgrade to iOS 9 -- at 92%.
OS X El Capitan and iOS 9 will release this fall, Apple said Monday, and each will be available to the general public for preview testing in July. Users interested in grabbing the previews can register with Apple's beta program on the company's website.