Native 4K with Radeon 5500 XT

[geoffoliver]

Hello. You need to set SMBIOS to iMac19,2. This Mac has 21.5-inch 4k screen by default. System preferences will show your screen resolution properly then.

When you use SMBIOS with 5K screen, system by default render 5K output and need to rescale it to your desire resolution what could cause overall system performance slowdown.

Nope, using iMac19,2 didn't make a difference. Same screen options, same scaling garbage. Worth a shot, though! Thanks