DELL U2723QX Connected to Macbook Pro at 4K@60MHz

The DELL U2723QX monitor, with default settings out of the box, connects to a Macbook Pro at a refresh rate of 30Hz. When dragging the cursor frequently, there's always a sense of lag—don't know if it's psychological or real. Previously I tried AOC's NANO IPS Master Edition, whose included TYPE-C cable could reach 60Hz. I figured DELL, being more professional (and expensive), shouldn't be worse than AOC, so I went through a lot of trial and error, and finally found a way to enable 60Hz without adapters or software.

As shown in the figure:

Press the OSD button on the bottom right of the back, and select in order: Display --> USB-C Prioritization --> High Resolution (the default is High Data Speed)

The screen will prompt you to unplug the cable or something—ignore that. After the screen comes back on, an extra column has appeared in the display settings; choose 60 Hertz.

The figure below shows data for the AOC U27U2DS Nano IPS Master Edition.

The image below shows the DELL U2723QX

By the way,

After putting the AOC Master Edition into sleep via the laptop, waking it back up takes about a 5-second delay; the new DELL wakes up instantly.