RE: UP3214Q/UP2414Q - 1/2 screen issue and/or No picture after powering off, then on
Thank you for this splendid suggestion! My newly delivered UP2414Q (from B&H) is Rev00 and I'm using it with a Geforce GTX 750Ti with driver 344.11 under Win7 Pro. It had the failure to wake from sleep and the windows resizing to 640x480 problems. Connecting a HDMI cable as well as the DisplayPort (set to be the 1.2 MST input source) solved ALL my problems, just as you note. While less than perfect, a $10 fix is OK with me.
I connect a 2 cables into Dell UP2414Q, 1 DisplayPort and 1 HDMI at same time, but only DisplayPort cable setup for 4K @ 60Hz, the HDMI cable its only physically connected.
After that the monitor had none of the problems mentioned in the topic, it is working perfectly. The only problem is during boot, the bios screen is not shown.