Custom Resolution Utility (CRU)

[marcgii]

I asked Claude to analyze my monitor EDID info and why I can't achieve the rated refresh rate (5k180) even though DSC clearly works on both HDMI and DP1.4. The explanation it gave of Samsung screwed up the EDID sounds plausible. But can anyone here confirm it is likely an EDID problem? The numbers it cites here are correct.

Quote:Your monitor's own Display Range Limits descriptor in the base EDID block declares a max pixel clock of only 2550 MHz. But the actual 180Hz timing in the DisplayID block needs 2932.5 MHz. The monitor is contradicting itself — one part of its EDID says "I support up to 2550MHz," and another part lists a timing that needs 2932.5MHz. There's also a horizontal frequency mismatch (range limits say 510kHz flat, but 180Hz needs 532.8kHz — over that too).
This is precisely the kind of internal EDID inconsistency that makes a driver throw out the higher mode: Nvidia's driver reads the Range Limits descriptor as the monitor's own stated ceiling, sees the DisplayID 180Hz timing exceeds it, and drops it as invalid — while 120Hz (1978MHz, comfortably under 2550MHz) passes cleanly and gets exposed. That lines up exactly with what you're seeing: 120 works, 180 doesn't, on both DP and HDMI, because this is an EDID-side defect, not a link-bandwidth one.