A line has been drawn through the iOS 11-compatible devices in ARKit, with only hardware with the A9 or A10 family processors able to use the augmented reality software.
A statement in Apple's developer information specifies compatibility to the two processors, with little other amplifying information. Apple notes that the "breakthrough performance" in the two processors allow for "fast scene understanding" without breaking down why the A8 can't technically accomplish the same feat.
The cut-off for ARKit means that the iPhone 6s, iPhone SE, and iPhone 7 families can use the technology. For iPads, the situation is a bit more restrictive, with the 2017 iPad, and the iPad Pros the only compatible models.
The iOS 11 release as announced supports the iPhone 5s and newer, the iPad Air and newer, and the latest iPod Touch.
Apple Vice President Craig Federighi announced ARKit at Monday's WWDC keynote. The project contains a developer toolset that it will make available to nearly instantaneously make the iPhone and iPad the largest AR platform in the world, according to the company.
In a demonstration of software produced by the new ARKit, the software identified a table surface, and applied a virtual coffee cup properly scaled to the surface. Following a lamp's addition to the surface, the lighting model adjusted dynamically as Federighi moved the lamp around the cup.