Custom Resolution Utility (CRU)

[wild0077]

(07-19-2020 04:21 PM)ToastyX Wrote:  

(07-19-2020 02:48 PM)wild0077 Wrote:  I own an LG 29WK600 (29" UWD 2560x1080 75Hz "HDR"), and am currently using it with an RTX2080S through DisplayPort (1.2 I believe, GPU-Z shows 5,4Gbps). Some time ago I was experimenting with nVidia custom resolution, typed in 3440x1440 just for the kicks and for my surprise it "worked", I mean, the image came right up, stuff on the screen were smaller, and no glitches that I could see. Typed in 3840x1600, and it also worked, same way described before, both at 75Hz. For some reason the image became a lot darker when using custom resolutions through nvidia panel, but at least I knew it might be possible.

After that, I decided to try CRU and see if I could create new resolutions properly, and I could, this time I went only for 3840x1600 75Hz, everything worked fine, the OSD from the monitor itself showed that resolution. However, from time to time the screen goes black for like 1 second, and than comes back. Happens at 3440x1440 75Hz as well, everything seems to work beautifully, and then out of the blue screen flashes black and comes back.

Naturally I tried lowering refresh rate, and both resolutions work flawlessly at 60Hz, no flashes at all, but since the monitor is rated 75Hz, I was hoping to actually be able to use those resolutions at the "desired" refresh rate.

What I would like to know, please, is if there is any possibility that the "flashing behavior" is something that can be solved by messing around with the settings on CRU? Or it sure means that the monitor simply cannot handle 75Hz at those resolutions?

With the NVIDIA control panel, did you change the active pixels or was it a scaled resolution? CRU doesn't create scaled resolutions. The blacking out sounds like a signal quality problem, or the monitor can't handle the resolution. I don't recommend using "LCD reduced" with higher resolutions. You might need to increase the vertical total for the monitor to handle it correctly.

Thank you for your answer.

I did noticed that active pixels part, the first time I tried the custom resolution with nvidia panel I saw that it showed 3840x1600 and active pixels still was 2560x1080, so the next time I made sure that it actually was showing 3840x1600. Creating it through CRU actually works, I just have this flashing issue at 75Hz, but 60Hz works like a charm, both resolutions (3440x1440 and 3840x1600). I've used 3440x1440 60Hz for a while before, but once you come back to 75Hz it's a little difficult to let go xD, especially because of the GSync compatibility, albeit not perfect, it does the job when the fps is hovering around 65 - 75.

I did not know that about the "LCD Reduced", back in the day when I first had contact with CRU I was pixel clock limited through DVI Single Link, so I'm kinda used to try and shave off those few MHz from it anyway I can xD. Thank you for your input, I will try using LCD Standard and Native to see if things improve.

Also, I have a question regarding the Ranges, more specifically the Horizontal Range. It comes factory 30-90KHz, but doing the math (1600*75=120 000 so 120KHz) should I edit that bit like I did in the pics? Or it won't matter at all?

Once again, thank you.