I'm curious about the metal feature set of two iMac models at 10.14 (Mojave)
iMac (27 inches, end of 2014) iMac15,1
iMac (21.5 inches, end of 2015) iMac16.1 or iMac16.2
The table on this page MTLFeatureSet shows:
The "iMac models of 2015 or later" will be macOS GPU family 2.
I hope that people with these models help verify, or that they can give an answer directly.
Two methods for control:
1. Hold down the Option key while selecting the Apple menu ()> System information.
In the sidebar, select Graphics / Screens.
2.Or terminal command
Metal: Compatible, macOS function set GPUFamily1 v4