Ui is very laggy on 5k HiDPI Display (Mac Pro 2019)

Hey,

so I've got the new Mac Pro, 16core with a Vega II GPU here, and attached is a Dell 5k Display.

One of the main reasons why I wanted this new machine so badly was because of how sluggish and slow the overall UI felt on my old Mac Pro from 2013.

Sadly, the new machine brought barely any improvements, leading me to the conclusion that the problem resides within the old, rotten core of Premiere (and other Adobe Apps like Lightroom Classic and After Effects that show the same behavior.)

Simply scrubbing through the timeline, or moving a clip around feels so laggy and slow, especially if I compare it to Davinci Resolve, FCPX or basically ANY other tool that runs normally on this machine. Just like as if everything was running at 15 fps only.

It gets a lot better when I force Premiere to open in Low-resolution mode in the info dialogue, but obviously, that's not a solution at all.

Here's a quick video where you can see what I mean:

http://chfilm.de/download/IMG_2187.mov

Here's another one: 

http://chfilm.de/download/premiere2.m4v

It doesnt look AS bad in the video, but trust me, it feels horrible, especially on such a new, 10k $ machine.

PLEASE Adobe, hear our prayers, and really focus on speeding up the UI on Retina-style Displays (basically everything above and including 4k is concerned by this). When I sit at some clients 6 year old machines Premiere runs MUCH more smoothly, just because they have regular 24" HD monitors attached, which is not an option for me anymore.