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OC monitor stuck on YCbCr422 and wont go to RGB
12-03-2020, 12:36 PM
Post: #1
OC monitor stuck on YCbCr422 and wont go to RGB
Hello, so I've managed to OC my monitor from 144hz to 162 successfully with no frame skipping and with Gsync stretched with it as well (48-162) at 1080p but I run into issue where the output color is stuck to only YCbCr422 and isn't giving me the option to switch to RGB. I used the exact same timings as Nvidia control panel for the overclock to make sure there wasn't any issues. If you also do it through Nvida control panel it it keeps it RGB but drops the output color depth from 8 to 6 (Same thing for the OC through CRU but with out RGB setting). Im assuming this has some thing to do with the bandwidth or the timings I used considering a forum post in the past...I know my cable isn't the problem since its DP 1.4 and its not my GPU as its a rtx 2070 super. I also tried the presets for the timings and it wont work unless its the reduced preset but even then its buggy sometimes so Im stuck with this. Is there any way to fix this while also maintaining hopefully everything from 144hz? Thanks in advance! Big Grin


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12-03-2020, 01:48 PM
Post: #2
RE: OC monitor stuck on YCbCr422 and wont go to RGB
You need to keep the pixel clock under 360 MHz. Try changing the horizontal back porch to 40.
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12-03-2020, 02:02 PM (Last edited: 12-03-2020, 02:04 PM by Phaedom)
Post: #3
RE: OC monitor stuck on YCbCr422 and wont go to RGB
I set it to 40 and its sitting at 358.60 pixel clock while also working fine, only problem now is that it gives me the option to use RGB but it resets back to default color settings in NCP when applying it

It also showing as 8bpc compared to 6 from before, dont know if that is it or just it being buggy
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12-03-2020, 03:04 PM
Post: #4
RE: OC monitor stuck on YCbCr422 and wont go to RGB
What are the default color settings that it resets to?
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12-03-2020, 09:21 PM (Last edited: 12-03-2020, 09:38 PM by Phaedom)
Post: #5
RE: OC monitor stuck on YCbCr422 and wont go to RGB
YCbCr422 with 8bpc and it being at limited for output range

Ok so I dropped 1hz from CRU and now Im able to do RGb with 8bpc at 161hz... It still not frame skipping either and I know its working as certain screen icons look much better now

Im happy with this but do you know what could be the reason for that and possibly easy fix? I appreciate help aswell Toast, Ive been scratching my head for few months on this and never could figure it out
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12-04-2020, 01:29 AM
Post: #6
RE: OC monitor stuck on YCbCr422 and wont go to RGB
The pixel clock might need to be under 357 MHz instead of 360 MHz. DisplayPort HBR can only do 8 bpc 4:4:4 up to 360 MHz pixel clock, which is why it drops down to 6 bpc or 4:2:2 when you go higher. There might be some overhead that the driver is not taking into account, which might be messing up the 357-360 MHz range.
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12-04-2020, 02:46 AM
Post: #7
RE: OC monitor stuck on YCbCr422 and wont go to RGB
Ah ok, so its either tweak some more with the timings until it works or just stick 1hz short and call it good. Thanks for help, can close/end this thread as I think 1hz short is fine and everything is working as intended with no issues. Again thanks and have a nice day! Big Grin
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