waydabber
commented
3 months ago Honestly, I am not sure, this seems to be some kind of bandwidth issue. Turning on deep color is not ideal as it needs more bandwidth (10+ bits per color instead of the traditional 8 bits) - to compensate for that, some devices my try to use chroma subsampling but if you see the conneciton as 4:4:4 then that is not happening either, so the system might not have better choice than to revert to a 30Hz mode.
On Apple Silicon you can understand rather easily what color mode, bandwidth etc is selected during display negotiation from the available options from looking at the kernel logs + matching the selected modes with available color modes in the IO registry. On Intel however the easiest way is to use the tool AllRez made by @joevt which I think can show the negotiated modes - this info might help you figure out what's causing the issue. A possible way to fix the problem is to use EDID override to remove color modes or connection options from the mix that might require higher bandwidth to produce or create custom timings that help you better max out the available bandwidth (60Hz might not work, but 50Hz might or 60Hz with even more reduced blanking etc).
Hello, I have a MBP 2017 with two thunderbolts and the anker hub 8-in-1 5 series usb-c which supports 4k 60Hz fine on my ipad Pro 2024, however no matter what resolution or bitdepth or anything else I can't seem to get past 30Hz on my macbook even with your application. The monitor is an LG C2 42-inches, latest webos, the input is designed as pc, hdmi deep colour 4k and 4:4:4 passthrough enabled, I'm running latest sonoma through oclp and latest betterdisplay (free trial, if this issue can be fixed I'd buy it immediately). any suggestions?