The first generation of 4K displays appear to be a bit of a hack. Note that it is possible to drive a 4K display at 60Hz using a single DisplayPort 1.2 stream, the limitation today appears to be entirely on the monitor side. By sending two tiles, each behaving like a 1920 x 2160 display (one half of 3840 x 2160), you can get around the bandwidth limitations of the current crop of display hardware.
Originally conceived as a way of daisy chaining multiple displays together off of a single DP output, the current crop of 4K displays use MST to drive a single display. To support 4K at 60Hz, you need to properly enable support for DisplayPort 1.2’s Multi-Stream Transport (MST) feature. Contrary to what Apple’s own support documentation lists, these 4K resolutions at limited refresh rates are supported via both HDMI and Thunderbolt 2/DisplayPort 1.2 on the new rMBPs.
That’s acceptable for use as a video preview display, but extremely frustrating for anything else (try watching a mouse cursor animate at 30Hz).
#Ssd for late 2013 mac pro pro
While the 2013 MacBook Pro with Retina Display can presently support outputting to either an 3840 x 2160 or 4096 x 2160 external panel, the maximum supported refresh rate is only 30Hz under OS X (and only 24Hz in the case of a 4096 x 2160 display). Alternatively you can connect up to six 2560 x 1440 displays using the Thunderbolt 2 ports at the back of the machine. You can connect two 4K displays via Thunderbolt 2/DisplayPort, and the third 4K display over HDMI. A huge part of the Mac Pro revolves around its support for 4K displays.