[SOLVED] El Capitan with 2560x1440 by HDMI (Ga-H97m-D3H / HD4400)
Recently I managed to fix the 1440p graphics using HDMI with El Capitain.
Yosemite has the same problem, so this solution probably could be used too. (maybe it works to 4k too, *not tested)
I'm using a mobo Ga-H97m-D3H and an i3-4170 / HD4400
Did two things:
1. run mac-pixel-clock-patch
https://github.com/Floris497/mac-pixel-clock-patch
2. Patched AppleIntelFrameBufferCapri.kext according this method. I used Kext Utility to inject the patched kext.
https://jonathansblog.co.uk/lg-34um95-osx-yosemite-resolution-bug
(I'm not sure if step two is really necessary. I did it first. After a reboot nothing happened. Then applied the mac pixel patch, did a new reboot and find 2560x1440 resolution in pref panel > Displays! \o/
UPDATE:
a. I'm almost convinced step 2 isn't really necessary.
b. Just did an automatic updated to 10.11.1. After reboot the screen resolution was lowered
. Then I run the latest version of mac-pixel-clock-patch, did a new reboot and the find again 2560x1440 resolution in pref panel > Displays!