I bought one of the new AOC 4K Monitors (a u2868pqu). It’s a great monitor, and available for only $800 in New Zealand. I ordered mine from mightyape and it arrived the next day.
Macbook air 11”
I tired an equivalent monitor on my 11” air and it wouldn’t even power up, so no go with the HD3000.
Macbook retina 15”
I have a 15” retina with the 650m GPU, and I plugged the monitor into the HDMI port and it just worked right away. You even have the option of using ‘more space’ mode, with is 3000px across (equivalent) with retina pixel subsampling. It looks great, and has plenty of space. The only problem is that it runs at 30hz, not 60hz. The same problem, 30hz, when plugged into the displayport port on my macbook too.
Macbook retina 13”
I tried out a new (2014) 13” retina, plugging the monitor into the mini display port, and still the asme problem, only 30hz. I’m not sure if this means the cable we’re using doesn’t support DP1.2, or the monitor just won’t do 60hz plugged into a mac.
Gaming PC
I ordered a gaming pc (from pbtech), I ordered it with a GTX 750 ti, which has displayport 1.2 and should have enough power to easily drive normal operating system stuff at 60hz. I’ll find out next week when the pc arrives. I’ve also ordered windows 8.1 since it has hidpi mode (as does sublime text and visual studio 2014). I doubt i’ll be able to do any gaming at 4k, although I will try really old games like quake 2. Maybe even TF2 if I run it at super low settings.