Custom Resolution Utility (CRU)

[ToastyX]

(09-21-2024 03:53 AM)ikonomov Wrote:  All my testing has been with DSC disabled which the monitor allows me to do in the OSD. HDMI 2.1 max FRL rate shows as 48 Gbps. After adding 4k/160Hz in a DisplayID 1.3 extension block (with CVT-RB timing) and running restart.exe (same with rebooting the computer) the selectable max refresh rate in NVCP drops from 144Hz to 120Hz, so not only is 160Hz not being added, but the 144Hz is actually being removed. I tried adding 144Hz in the same DisplayID extension block just to test, but it's still not being added and the max shows as 120Hz.

Try deleting the extension override data block. 144 Hz will be removed because the hidden extension block is not included, but you should be able to add 144 Hz back in.

[ikonomov]

(09-21-2024 04:24 AM)ToastyX Wrote:  Try deleting the extension override data block. 144 Hz will be removed because the hidden extension block is not included, but you should be able to add 144 Hz back in.

After deleting the extension override data block the 144Hz now shows in NVCP as before. Unfortunately 160Hz still doesn't show. My assumption has been that I can force a given resolution and refresh rate. Since 4k/160Hz/8bit needs less than 48 Gbps with CVT-RBv2 and CVT-RB timings I thought that it would be at least possible to test and see how the monitor would handle it. It's interesting that a few 4k 160Hz monitors with full bandwidth HDMI 2.1 have been released now and all of them that do not have DSC support over HDMI seem to have a 144Hz limit for HDMI 2.1 connections. Any explanation for this would be greatly appreciated. Thank you.

[ToastyX]

(09-21-2024 05:00 AM)ikonomov Wrote:  After deleting the extension override data block the 144Hz now shows in NVCP as before. Unfortunately 160Hz still doesn't show. My assumption has been that I can force a given resolution and refresh rate. Since 4k/160Hz/8bit needs less than 48 Gbps with CVT-RBv2 and CVT-RB timings I thought that it would be at least possible to test and see how the monitor would handle it. It's interesting that a few 4k 160Hz monitors with full bandwidth HDMI 2.1 have been released now and all of them that do not have DSC support over HDMI seem to have a 144Hz limit for HDMI 2.1 connections. Any explanation for this would be greatly appreciated. Thank you.

You should be able to. Either the monitor is not actually 48 Gbps, or there's some limitation on NVIDIA's end with EDID overrides. Did you try CVT-RB2? 160 Hz with CVT-RB exceeds 40 Gbps but CVT-RB2 should fit within 40 Gbps. "Exact" would be even lower in this case. What about with NVIDIA control panel custom resolutions?

[ikonomov]

(09-21-2024 02:07 PM)ToastyX Wrote:  You should be able to. Either the monitor is not actually 48 Gbps, or there's some limitation on NVIDIA's end with EDID overrides. Did you try CVT-RB2? 160 Hz with CVT-RB exceeds 40 Gbps but CVT-RB2 should fit within 40 Gbps. "Exact" would be even lower in this case. What about with NVIDIA control panel custom resolutions?

I've tried both with CVT-RB and CVT-RB2. The problem is that for some reason the newly added 4k 160Hz resolution isn't even being added to NVCP (or display settings in win 10). I was able to add the 144Hz with your suggestion, however, so I wonder why 144Hz was added but not 160Hz. NVCP doesn't allow adding a custom 4k resolution with 160Hz. The test passes but clicking on Save doesn't add the custom resolution to the list. It looks as if something is preventing EDID overrides above 144Hz at 4k or perhaps any resolutions that exceed that frequency at 4k are being ignored. Judging by reviews of other 4k 160Hz monitors it appears that they share the same limitation. For example LG 27GP950-B https://www.rtings.com/monitor/reviews/lg/27gp950-b or Cooler GP27U https://www.rtings.com/monitor/reviews/c...pest-gp27u only support 4k at 144Hz using their 48Gbps HDMI 2.1 connection but can go up to 160Hz using DP 1.4 and DSC. It begs the question where this limitation comes from since 4k/160Hz/8bit using CVT-RB2 timings should be well below 48Gbps. In fact using lower timings even 10bit should be possible.

[ToastyX]

(09-21-2024 02:50 PM)ikonomov Wrote:  I've tried both with CVT-RB and CVT-RB2. The problem is that for some reason the newly added 4k 160Hz resolution isn't even being added to NVCP (or display settings in win 10). I was able to add the 144Hz with your suggestion, however, so I wonder why 144Hz was added but not 160Hz. NVCP doesn't allow adding a custom 4k resolution with 160Hz. The test passes but clicking on Save doesn't add the custom resolution to the list. It looks as if something is preventing EDID overrides above 144Hz at 4k or perhaps any resolutions that exceed that frequency at 4k are being ignored. Judging by reviews of other 4k 160Hz monitors it appears that they share the same limitation. For example LG 27GP950-B https://www.rtings.com/monitor/reviews/lg/27gp950-b or Cooler GP27U https://www.rtings.com/monitor/reviews/c...pest-gp27u only support 4k at 144Hz using their 48Gbps HDMI 2.1 connection but can go up to 160Hz using DP 1.4 and DSC. It begs the question where this limitation comes from since 4k/160Hz/8bit using CVT-RB2 timings should be well below 48Gbps. In fact using lower timings even 10bit should be possible.

What about refresh rates other than 144 Hz? Try 140 Hz to verify if it's allowing EDID overrides. If that works, try between 144-160 Hz.

[ikonomov]

(09-21-2024 03:06 PM)ToastyX Wrote:  What about refresh rates other than 144 Hz? Try 140 Hz to verify if it's allowing EDID overrides. If that works, try between 144-160 Hz.

140 Hz worked. The testing revealed the following frequencies at 3840x2160 that I was able to create and then have them available in NVCP:

in NVCP
CVT-RB: up to 99 Hz

in CRU
CVT-RBv2: up to 148 Hz
Exact: up to 149 Hz
Exact reduced: up to 155 Hz

The limiting factor for resolutions created in CRU seems to be a pixel clock of up to around 1350 MHz (155 Hz Exact reduced uses 1348.50 MHz). NVCP allows me to set the color depth to 10 bit at 155 Hz, so it seems perhaps some sort of conservative calculation is taking place that allows only resolutions that are able to output 10 bit color.

Do you know what could be the effects of using such low timings as Exact reduced?

[ToastyX]

(09-21-2024 05:09 PM)ikonomov Wrote:  140 Hz worked. The testing revealed the following frequencies at 3840x2160 that I was able to create and then have them available in NVCP:

in NVCP
CVT-RB: up to 99 Hz

in CRU
CVT-RBv2: up to 148 Hz
Exact: up to 149 Hz
Exact reduced: up to 155 Hz

The limiting factor for resolutions created in CRU seems to be a pixel clock of up to around 1350 MHz (155 Hz Exact reduced uses 1348.50 MHz). NVCP allows me to set the color depth to 10 bit at 155 Hz, so it seems perhaps some sort of conservative calculation is taking place that allows only resolutions that are able to output 10 bit color.

That must be a GPU limitation because 40 Gbps would be 1485 MHz and 48 Gbps would be 1782 MHz for 8 bpc. I wonder if that's the single-head limit for the GPU. With DSC enabled, the GPU is able to borrow other heads to support higher pixel clocks, but then the driver disables custom resolutions and EDID overrides.

(09-21-2024 05:09 PM)ikonomov Wrote:  Do you know what could be the effects of using such low timings as Exact reduced?

The main issue is the GPU won't clock down when idle if the vertical blanking is too low. You can reduce the horizontal blanking as well if you don't need HDMI audio. Try multiples of 8 for the horizontal values. You might be able to squeeze in 160 Hz if the monitor can handle low blanking values.

[ikonomov]

(09-21-2024 06:11 PM)ToastyX Wrote:  The main issue is the GPU won't clock down when idle if the vertical blanking is too low. You can reduce the horizontal blanking as well if you don't need HDMI audio. Try multiples of 8 for the horizontal values. You might be able to squeeze in 160 Hz if the monitor can handle low blanking values.

I found your post here which helped me to understand that it's the Nvidia that's likely rejecting the resolutions in the EDID, but when I use the values you provided the resolution is still being rejected. Maybe they have changed something in the latest drivers or possibly it's something specific to HDMI 2.1 or the monitor's firmware?

The lowest accepted horizontal blanking that worked was 56 pixels but strangely it locks the color depth to 10 bit. Increasing it to at least 64 allows selecting either 8 or 10 bit as normal but if it's less than 80 (the value used by CVT-RBv2) it results in displaying blank screen at 720p. The highest resolution that I was able to squeeze in below 1349 pixel clock (turns out it's exactly that value) is 158 Hz using 80 pixels of horizontal blanking. I increased the vertical blanking as much as possible and the included screenshot shows the best setting that I came out with, maybe somebody will find it useful. Thank you for your help.

   

Edit: The GPU (RTX 3070) seems to be able to clock down normally when idle. I found no other issues reported here.

[Macak]

Hello guys.
Im having problem and i hope u wiil help me to solve.
I have asus pg279q monitor.
I want to make custom refresh rate at 130Hz.
When i do that i have out of range error on my screen when i set that refresh rate.
My monitor at default have 24hz,60hz,85hz,100hz,120hz and 144hz refresh rate choices.
I dont get it why I get "out of range" error at 130hz?
Any tips pls?What I do wrong?
Tnx in advance.
cheerZ

[ToastyX]

(09-22-2024 04:27 PM)Macak Wrote:  Hello guys.
Im having problem and i hope u wiil help me to solve.
I have asus pg279q monitor.
I want to make custom refresh rate at 130Hz.
When i do that i have out of range error on my screen when i set that refresh rate.
My monitor at default have 24hz,60hz,85hz,100hz,120hz and 144hz refresh rate choices.
I dont get it why I get "out of range" error at 130hz?
Any tips pls?What I do wrong?
Tnx in advance.
cheerZ

Monitors with NVIDIA's G-SYNC processor usually don't support custom refresh rates. You shouldn't need it with G-SYNC anyway. Just cap the frame rate if you want more consistent frame rates.