Updated 3/25/2015: Ars Technica picked up a MacBook Air for testing, and is reporting that the Air is also able to handle 4K at 60Hz via a DisplayPort 1.2 connection. The Air still does not appear on Apple’s website as officially supporting 4k at 60Hz.
Apple’s MacBook Pro 13 with Retina display has long been the laptop of choice for mobile professionals, but it’s recently suffered from a noticeable oversight; lack of support for the latest 4K resolution. Due to its older Intel HD graphics solution, it was not able to output 4K resolution at full 60Hz resolution.
Now that has changed. The 13-inch Pro with Retina, which has received a graphics upgrade and Thunderbolt 2 support for additional bandwidth, is fully capable of driving a 4K monitor over Thunderbolt/Mini-DisplayPort. It’s now listed on Apple’s support page, but that page claims that Mac systems will only work with certain monitors.
We went one better and purchased the new system to test for ourselves, and we can confirm it works without issue alongside several 4K monitors not listed on Apple’s official support page. In other words, it should be able to handle any current 4K display with a DisplayPort input (which is all of them, to our knowledge).
Interestingly, the early 2015 MacBook Air is not listed. That strikes us as odd because the graphics solution in the refreshed Air should have no trouble handling the resolution. We reached out to Apple to ask if the Air did support 4K, and were told that the support page is accurate (meaning it does not). Ars Technica, on the other hand, claims that the Airs do support UltraHD.