Although Apple claims its latest MacBook Air will officially support external monitors that have a resolution of up to 2,560 pixels by 1,600 pixels, recent tests have shown that the device can actually drive an external 4K display at a full 60 Hz. According to the folks over at Ars Technica, the early 2015 MacBook Air with Dell P2415Q 24-inch 4K display ended up yielding positive results. When attached, the Air was able to identify the attached monitor at a 4K resolution, switching the interface into HiDPI mode.

Refresh rates from the test confirmed that the display was running at 60 Hz and that the publication said that the interface components were “more than smooth enough for desktop use.” Issues arose when performing animation-intensive actions such as entering full-screen mode with clear visible frame lag being the culprit. This shows that the display pushes the Intel HD 6000 graphics chip near its limits. The limit is exceeded when using OS X’s built-in resolution scaling functions with the integrated GPU turning animations into “flip books” when asked to render higher resolutions, even scrolling performance is said to suffer in the situation.

Although the MacBook Air’s Tech Specs page doesn’t list 4K compatibility, the early 2015 Air is listed on Apple’s 4K display support document. It’s only shown with the capability to push 30 Hz or 24 Hz rather than the 60 Hz that was discovered by Ars Technica. This isn’t out of line with Apple’s spec history as the company often lowers the “official” capabilities of its products below what they are theoretically capable of. Still, it’s interesting to know what Apple’s products are really capable of.

Source: Ars Technica