I have a Dell UP3216Q that I cannot get to display 60Hz over DisplayPort. I have the latest drivers and the drivers wont let me set the refresh rate to 60Hz, it simply states that the refresh rate is not supported. My MacBook Thunderbolt port outputs a 60Hz display just fine.
Also, I have a U3011 that I'm connected via HDMI output to the DVI input of the monitor, and that is limited to 1080p at 60Hz. The same cable works on my MacBook at 60Hz just fine. Any idea what's going on? Thank you!