OS X Lion incorporates support for displays packing four times as many pixels as they do today. So perhaps we’ll see Macs with their own version of the Retina Display soon.

Currently the “HiDPI” mode remains inaccessible unless you’ve downloaded Apple’s Xcode software development tool. It contains a graphics test application called Quartz Debug and it enables HiDPI modes — which allow developers to supply 2x-enlarged images to support double-high resolution displays — in Lion’s Displays control panel.

Lion features icons in sizes up to 1024×1024, and a desktop background at a resolution of 3200×3200. Like the iPhone 4′s Retina Display, HiDPi modes mean that user interface elements will remain the same size, but everything will be twice the resolution and twice as detailed.

Imagine a 27-inch iMac (my model of choice) with 3840 x 2160 resolution. The current high-end model has “only” 2560 x 1440 resolution. Such a display requires quite a bit of processing power. But a top-of-the-line iMac with Sandy Bridge processors (or their descendants) could certainly handle it.

Of course there are problems to be resolved. Consider this post (http://macte.ch/2oGeK) from Tim Ricchuiti at “The Elaborated”: “If Apple were to do something like [retina displays on Macs], the biggest question I would have is whether or not they’d put something into place for users who genuinely do want much smaller UI elements and much more screen real estate.

That is, if Apple were to double their UI, and then use the 2×1080p resolution for the 27-inch iMac, there’s a sense in which current 27-inch iMac users would feel like they were actually losing screen real estate from their current 2560 × 1440 displays. But that’s why Apple’s Apple and I’m a guy writing about them: if and when Retina Displays do come to the Mac, they will have thought that issue through and either solved it, or decided that the set of users who would be upset by it isn’t a large enough group to hold other users back.”

Or perhaps a high-end iMac with a retina display and other models without it for those who don’t want it?

— Dennis Sellers