4k display on macbook pro 2011 doesn't work
I have recently bought a philips 4K display (272P4). My macbook pro (early 2011, 2gHz i7 machine with AMD Radeon HD 6490M 256 MB) should be capable to handle the display (according to apple tech specs). However, hdmi via 4k dp to hdmi connector only does 1080p (or i) and display port doesn't function (bought a mini DP to DP cable). Any suggestions on how to fix this?
MacBook Pro (15-inch Early 2011), OS X Yosemite (10.10.1)