Display Overrides for macOS (Big Sur)

This repository is for display overrides to make (my) monitors work better on macOS.

For Catalina and older, see mafredis catalina-branch.

Goals

• Force HiDPI modes for screens that are not supported (by macOS)
• Force picture modes on misbehaving screens
• Fix displays detected as TVs
• Make sure Night Shift works on external displays
• Allow picking HiDPI modes in Display preferences like for retina displays (less realiant on RDM)
• Custom icons for displays

Usage

1. Create overrides (DisplayVendorID-*/DisplayProductID-*.plist) or use the existing ones
2. Open Terminal and run sudo install.sh from the project folder
3. Reboot

After rebooting, the "Display" system preferences should show an updated display name in the title bar and if scaled resolutions are shown (option-click on "Scaled"): additional resolutions are available.

See screenshot below from my Dell U3818DW.

The highlighted resolutions correspond to a scaling of 80% respectively 75% of the native screens resolution.

Notes

• Since macOS Mojave we no longer seem to need RGB edid overrides, they seem to be ineffective
  • We can use DisplayIsTV => false instead
• Tweak target-default-ppmm to enable selection of HiDPI modes in System Preferences -> Display
  • Also requires adding the appropriate HiDPI resolutions
  • How do we calculate optimal ppmm for display x resolution?
  • See DELL U2715H override for an example

Dumping display EDID

Create a dump for each display connected to your Mac.

n=0; \
ioreg -lw0 | grep "IODisplayEDID" \
    | while read line; do \
        ((n++)); \
        name=display-${n}.edid; \
        sed "/[^<]*</s///" <<<"$line" | xxd -p -r >$name; \
        echo "Created $name"; \
    done

Resources

• Adding/Using HiDPI custom resolutions - tonymacx86.com
• Display Override PropertyList File Parser and Generator with HiDPI support
• edid-decode
• avibrazil/RDM - Easily set Mac Retina display to higher unsupported resolutions
• usr-sse2/RDM - Fork, supports editing, icons, etc.
• xzhih/one-key-hidpi