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?

[MasonAlice]

Does the method of editing EDID still work on the latest macOS versions (macOS Sequoia)? For example, to force RGB output.

[waydabber]

Yes, it should work. For RGB you can simply use the Color Mode menu though (on Apple Silicon).

[MasonAlice]

If I have written the RGB output into the EDID, does that mean I no longer need to enable Color Mode Configuration Protection( on Apple Silicon )? It should automatically output RGB after booting up.

I want to edit the EDID in order to force RGB output and disable GPU dithering. Is that possible?

[waydabber]

Right. However on Apple Silicon the modified EDID will not be applied during boot (unless you wrote it to the display itself, very few displays support such a thing), so the app needs to actively apply it when it is launched. So in fact there is no much difference between using Config Protection and editing the EDID for RGB. Therefore I recommend using the Color Mode menu and Configuration Protection. A third way is to persist the change by editing the windowserver config file, but that will be reverted from time to time due to various reasons so that is a somewhat problematic approach.

[MasonAlice]

Thank you for your patient explanation. The reason I purchased BD is because the display connected to my Mac Mini M4 kept flickering. It seems that if I set RGB 8-bit full range output and disable GPU dithering in BD, the flickering stops.

I've been troubled by this issue for a long time, and BD is an excellent software. It really solved my problem.