So, nuances of MST aside, are you saying that this driver allows the SP3 to drive 4k at 60Hz? Is it likely to work similarly (i.e., at 60Hz) for other 4k monitors (noting that even Microsoft says the SP3 can drive a 4k monitor at only 30Hz)??
I have the same monitor and experienced the same issue. I am not sure whether the fault lies with the monitor or the SP3.
But there is hope. Surprisingly, however, I do get 4K resolution if I connect the monitor via one of the monitor's HDMI ports when connecting the SP3 with a miniDisplayPort...
No, incorrect. Monitors and cables that work when plugged into the port on the device don't work on the docking station. The docking station has distinct requirements than the device itself.
The third post in this thread is relevant:
http://forums.wpcentral.com/microsoft-surface-pro-3/305711-%5Bsolved%5D-surface-pro-3-docking-station-wont-ouput-video-even-w-same-cables-worked-sp2-dock.html
I forgot to mention, I have tested the same dock with the same DisplayPort cable and the same mini DisplayPort adapter using two different SP3's (both i5/8M/256G) and two different monitors (HP ZRW30 & Samsung U28D590D); in both situations each SP3 works only when the cable/adapter is plugged...
Sorry to tell you, I applied the 08/19 update immediately before using my dock for the first time.
What you are describing--external monitor flashing black for a few seconds--is exactly what I am experiencing. To be specific, it's a little unpredictable. The monitor will be on for a few seconds...
I am also experiencing a problem with the mini DisplayPort on my Surface Pro 3 dock. I am connecting a HP ZR30w monitor via a mini DisplayPort to DisplayPort adapter. I have no problems if I connect to the port on my SP3; however, if I connect through the dock, the external monitor will flicker...