Does OS X support 3x scaling yet?

Question

In Xcode 6.1 I'm seeing a "3x" and "All" resolutions available for my Mac OS X target. I wonder if the "3x" option is used for Mac apps? If it does, which configurations that calls for the 3x artworks?

Does the new 5K iMac makes use of those 3x artwork resolutions? Or some Mac pro configurations?

If those 3x artworks are not present, does it render the PDF version instead of upscaling the 2x ones?

Answer 1

The only reason 3x is available is because in the Devices attribute, you've chosen Universal – if you choose Device Specific and check only Mac, you'll see only 1x and 2x.

The 5K iMac just uses 2560x1440 @2x (hence 5120x2800 pixels), not 3x in any case. iPhone 6 Plus is the only device to make use of 3x images, as far as I know.

Answer accurate at time of writing! (17/04/15)