I recently bought the Dell XPS9370 with 4K touchscreen ,i5 and intel UHD 620 graphics.
I noticed that windows 10 UI animations are laggy and not smooth when using 4k resolution.
really it seems that the overall performance in 4k is not so good.
all drivers are updated and windows is update with no all updated in "windows update".
when I switched to FHD resolution 1920*1080, all UI animation ran silky smooth.
please help to fix the issue because decreasing the resolution is not a proper fix.