MacBook Pro with Retina display (Late 2012) not outputting anything above 1080p I know it won't support 4k but it should at least do 1440 right? I can't get higher than 1080p...



UPDATE:
I pressed alt and clicked "scaled" to unlock the extra resolutions as suggested by Buscar웃. It gives me more options but onfortunately still nothing higher than 1080p :(



This macbook is quoted as supporting "up to 2560 by 1600 pixels on up to two external displays" and it does so with the thunderbolt cinema display. Surely it should be able to do the same with my new 4k monitor? If it matters, the display I'm using is the AOC U2868PQU. I'm not using "mirroring" as suggested by LaX.
I managed to get full 3840×2160 @30Hz using mini-displayport cable and an app called SwitchResX. Here are my custom settings, you need to reboot the machine to apply them:



As a word of warning, this does make things eye-bleedingly small. (Pretty cool though - full-size)



Personally, I found the ‘scaled’ resolution of 1920×1200 to be the best for me because it uses HiDPI to give you that retina feel you’re used to. It will look like 1920×1200 but actually use more pixels to paint it. Here are the settings:



This is much more sensible (although I would like it smaller to be honest).
The downside is that you lose some of the screen down the sides. Let me know if you have any better suggestions.

If you find the colours going a bit funny, I used SwitchResX to change the color profile to sRGB IEC61966-2.1 like this:



For more details, go to my blog post here: http://www.mattburns.co.uk/blog/2014/09/30/running-the-4k-aoc-u2868pqu-and-intel-hd4000-graphics/