Just put in a 7950 (Mac Pro 5,1) to drive a Dell P2815Q 4K monitor... choosing the 4K res. (3840 x 2160), all the interface elements are tiny... and unusable. I thought the idea of adding support for 4K in Yosemite was to make it act like the 5K iMac, where all the interface elements (menu bar, fonts, title bars, etc.) are the same size at 5K as they are at standard res... what am I not getting? Is there some setting / set-up that needs to be done?