Question: LG UltraFine 4K‑display + MacBook Pro (13-inch, 2016)
I use my LG UltraFine 4K‑display with my macbook pro solo via usb-c connection.
I don't use some external power supply to my macbook pro.
As soon as i connect the external display my macbook is reacting very slow, perfomance goes down.
Also Bluetooth connections are getting laggy, like my mouse.
I tested some other external display via hdmi connector + external power supply, and the performance is perfect.
I am on High Sierra 10.13.3 (17D47)
I did not test my setup with usb-c connection to the monitor and external power supply, but the reason I got this specific setup was to avoid additional cables and external power supply to my macbook pro.