According to the docking station specs, maximum resolution for using triple display is x3 QHD (2560 x 1440) @ 60Hz with HBR3 Displayport bandwidth.  So ultra wide monitor is a no go.  
Hello, I have a Dell Precision 7550 running Windows 10 connected to a WD19DCS dock. Overall it performs well. Currently I have 3 monitors connected to the dock (the dock has 2 DisplayPort and 1 HDMI port):   WalMart has a sale on a nice ultra wide QHD monitor at 3440 x 1440, so I thought I'd get that to maximize the screen space so I bough the monitor. Here's what I want to have: But when I connect them, the large monitor (2) is forced to a maximum resolution of 2560 x 1080. I tried moving the monitors around to the different ports, and the result is always the same - one of the monitor resolutions gets derated. Does anyone know if this is a limitation of the docking station? Or of the laptop? Any workarounds available?  If not, is there maybe a better docking station I can get to achieve my maximum tricked-out monitors? Where can I find out the limits of monitors and resolutions? Thanks in advance for the  help. -- Steven    
Maximum total monitor(s) resolutions? Precision 7550/WD19DCS