I am on a macbook pro 13inch mid 2014 and managed to get the U28D590 working for a 1920x1080 retina resolution (3840x2160 real resolution).
After upgrading to El Capitan, I lost the ability to do the same.
I disabled SIP to move the Display file profile where it should be.
That works and the file is valid however the setup that I had working seems to be ignored now.
Right now I am stuck at 2560x1440 (from what the OSD information tells me on the U28D590).
Current file:
MacBook-Pro:~$ plutil /System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-4c2d/Disp layProductID-b80
/System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-4c2d/Displ ayProductID-b80: OK
MacBook-Pro:~$ more /System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-4c2d/Disp layProductID-b80
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>DisplayProductName</key>
<string>Samsung U28D590</string>
<key>DisplayProductID</key>
<integer>2944</integer>
<key>DisplayVendorID</key>
<integer>19501</integer>
<key>IODisplayEDID</key> <data>AP///////wBMLYALAAAAADQXAQS1PSN4Ol+xoldPoigPUFS/74BxT4EAgcCBgKnAswCVANEAC8 IAoPBwPoAwIDUAX1khAAAaVl4AoKCgKVAwIDUAX1khAAAaAAAA/QAySx6GNgAKICAgICAgAAAA/ABVMj hENTkwCiAgICAgAfUCAwzwIwkHB4MBAAACOoAYcTgtQFgsRQBfWSEAAB4AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAlw==</data>
</dict>
</plist>
I have tried enabling other resolutions by modifying the Display file above and but the monitor does not want to go beyong 2560x1440 (from the OSD).
Has anybody got that screen showing a 1920x1080 retina resolution on El Capitan?
Thanks.