How to edit EDID on Apple Silicon + some examples (4K@120Hz, forcing RGB, tiled displays)

[waydabber]

Here is a brief example of how to edit the display's EDID and apply the modified EDID to Apple Silicon. This example deals with 4K@120Hz support over some HDMI dongles for M1 Macs:

• https://forums.macrumors.com/threads/mac-mini-4k-120hz.2267035/post-31952813

An other practical example is disabling YCbCr and forcing RGB color encoding:

• How do I force RGB color mode for my display (instead of YCbCr)? #1473

Setting up tiled displays:

• Novastar LED Controllers / TILED displays / Custom EDID #713 (comment)

[law94air1976]

how to do this on intel mac?

[waydabber]

on Intel macs you have a section for EDID override under configuration overrides (last entry, it should appear below Display type as an expandable section). You can upload the custom EDID there. You need to restart the mac for the custom EDID to take effect.