I just installed a new 960 FTW.  I am using Windows 10 Home 64 bit, and I have installed the latest drivers from Nvidia.    I have my monitor plugged into the GPU via Displayport cable.  My monitor handles resolution up to 3840x2160, and I have my resolution set to that in Windows settings.  When i pull up GeForce Experience app and look at "My Rig" it shows Current Resolution 3840x2160.  However, when i go to a website that detects the resolution being displayed, it tells me my resolution is 2560x1440.  I tried another resolution detecting website and got the same result.  What do I need to do to get it to display 3840x2160?