I have a ThinkPad T450 with Intel 5500 graphics that I was happy connecting to an inexpensive Samsung monitor at home and a Dell P2815Q at the office using an HDMI-to-mini-DisplayPort adapter. The Dell just runs at 3840 resolution and the Samsung at 1920.
I inherited a Dell U3011 last week to use at home and it has a maximum resolution of 2560x1600. When I connect it to the ThinkPad DisplayPort using the existing HDMI adapter or a new DVI adapter, all I can get is 1920x1200. Can I ever get the higher resolution, with or without a docking station?