Unable to get 2560 X 1440 resolution to work

Both the Intel and Nvidia GPU seem to have a max resolution that is dependent on the connection type.

From Intel Graphics Reference and nVidia the max resolution:

• Display Port: 2560x1600
• HDMI/DVI: 1920x1080
• Analog VGA: 2048x1536

The Intel link is less clear that HDMI and DVI are less than the DisplayPort but there are a number of other sources that claim this (here, here and here).

The specs to your laptop show that it only has HDMI out which appears to be the limiting factor. You would need to have a display port out on your laptop and into your monitor to use the larger resolution.

To answer your other questions:

• Yes your max resolution will be limited by the max that the video adapters will support.
• Yes you have two adapters but the OS is supposed to dynamically handle which one is used (see here, here and here)

Update to my last post: While the DisplayPort cable didn't work when connected to my Dell Laptop docking station's DisplayPort, and while it didn't work if I connected it to my laptop's DisplayPort while the laptop was in the docking station, once I removed the laptop from the docking station and connected the cable to the laptop's DisplayPort and rebooted, VOILA, I finally got full resolution on the Dell Ultrasharp. Hope this helps someone else...it suggests maybe there's something wrong with the docking station's DisplayPort. No problem, I'll just not use it. Once you get the Ultrasharp displaying in full resolution, you will be a Very Happy Camper, so don't give up until you've tried all possible combinations. Good luck; hope this helps someone else!