Creating a CVT-RB custom resolution on macOS without SwitchResX?
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Creating a CVT-RB custom resolution on macOS without SwitchResX?  


Active Member
Joined: 11 months ago

I have a 4K TV, and it gets unstable at [email protected] over HDMI. To fix this in Windows and Linux, I created a custom [email protected] resolution with CVT-RB (reduced blank) timings (on Windows via AMD's GPU control panel, and on Linux via Xorg.conf snippet with a generated modeline).

SwitchResX seems to be able to do this under macOS, but I can't afford a license for it currently, and would prefer a solution longer than 10 days.

I'm wondering if anyone has any other possible solutions?

I've replaced my GPU and 4+ HDMI 2.0 [email protected] certified cables; I'm thinking it's down to the display either being defective, or it providing bad and/or untested EDID for that res (this only happens at [email protected]; other 60Hz resolutions, along with [email protected] are fine).

MacBook Pro (Retina, 13-inch, Mid 2014)
AKiTiO Thunder2
XFX Radeon RX 580
macOS Catalina 10.15
Fedora Workstation 31 Beta

2014 13" MacBook Pro [4th,2C,U] + RX 580 @ 16Gbps-TB2 (AKiTiO Thunder2) + Linux Fedora 30 [build link]  

Noble Member
Joined: 3 years ago

$20 for SwitchResX.

You can create an EDID override in a new file for your display in /System/Library/Displays/Contents/Resources/Overrides
Look at all the examples to see how they work.

Use the following command to get the EDID on macOS:
/System/Library/Extensions/AppleGraphicsControl.kext/Contents/MacOS/AGDCDiagnose -a > AGDCDiagnose_a.txt 2>&1

Or use Monitor Asset Manager (moninfo.exe) in Windows.

Convert between hex and binary using xxd command in macOS.

In your override file, you can patch the EDID or override the entire thing. Find an EDID editor. Maybe for macOS.

Mac mini (2018), Mac Pro (Early 2008), MacBook Pro (Retina, 15-inch, Mid 2015), GA-Z170X-Gaming 7, Sapphire Pulse Radeon RX 580 8GB GDDR5, Sonnet Echo Express III-D, Trebleet Thunderbolt 3 to NVMe M.2 case