I have been dealing with the details of running a current gen 4K display. The one I got is identical to the one Apple has shown in photos with Mac Pro. (Sharp PN-K321, I have Asus PQ-321). A little detail that hasn't been mentioned much is how these displays run. In order to get to 4K with today's parts, the displays actually run as 2 separate panels, each one is 1920x2160. When you get boot screens, the right side half fires up, then the left. The speed of the pixel clock maxes out on one connection and requires this dual wide setup. Windows drivers make up for this using multi-display tech. AMD has called this "Eyefinity" and Nvidia has their own name. The driver looks at the PQ-321 as 2 displays but links them. This way they are able to run the display at 60HZ. You can do this with either a single DP 1.2 connection, or by "doubling down" on the HDMIs. Either way, the drivers compensate invisibly. In OSX 10.9 there is currently NO WAY to run the display at 60Hz. So, as it stands, 4K is kind of NOT READY for OSX yet. At 30Hz, you can see the mouse "hopping" across the screen. Boot into WIndows at 60 Hz and it smooths out nicely. In effect, the whole 4K package isn't "gelled" yet. I imagine that future 4K displays will not require this kludge. There is no way that serious editing folks are going to settle for OSX 4K being half as good as booting into Windows. I was thinking about this last night, and it hints at something. Either: 1. Apple is going to "one more thing" us and have a 4K display announced for shipment in near future. It will be designed for Mac Pro and will solve this 60Hz dilemma. 2. Apple is going to include a 10.9.1 update for nMP that includes something akin to "Eyefinity" for the Dx00 cards to enable this monitor to run at 60Hz. I have tried using ChangeRes-X without results. Part of it is I can't understand how to use the app, but Marcel wrote me back, he thinks there is a max pixel clock supported by OSX and running at 60Hz would exceed that. So, either new display in the wings, or OS support for a Windows feature that we previously haven't had...or Apple is going to go stone deaf and pretend they don't hear all of the "Pros" complaining about being stuck at 30Hz in OSX. Next 45 days will be interesting.