Custom Resolution Utility (CRU)

[ToastyX]

(06-25-2026 12:56 AM)marcgii Wrote:  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.

The range limits descriptor is old and can't go higher than 2550 MHz pixel clock or 510 Hz/kHz, so those are the maximum values. NVIDIA's driver doesn't listen to the max pixel clock or horizontal range anyway, only the refresh rate range for adaptive sync.

The real issue is it's a GPU limitation. You need a 5000-series GPU to get 5120x2880 @ 165/180 Hz. Samsung doesn't seem to specify this anywhere, but the ASUS XG27JCG also supports 5120x2880 @ 180 Hz, and they mention a 5000-series GPU is required for 180 Hz.

I don't know what the limit for 4000-series GPUs is, but I would assume it would be 2x the single-head limit, so 2700 MHz. In theory, you could squeeze in 5120x2880 @ 165 Hz with reduced blanking, but not 180 Hz without very tight blanking intervals. Unfortunately, NVIDIA's driver won't let you experiment because it doesn't support custom resolutions or EDID overrides when using two heads for bandwidth.

[marcgii]

Quote:I don't know what the limit for 4000-series GPUs is, but I would assume it would be 2x the single-head limit, so 2700 MHz. In theory, you could squeeze in 5120x2880 @ 165 Hz with reduced blanking, but not 180 Hz without very tight blanking intervals. Unfortunately, NVIDIA's driver won't let you experiment because it doesn't support custom resolutions or EDID overrides when using two heads for bandwidth.

Thanks. 2700 being the limit is a good theory because there are some versions of the display which cap at 165 that do work with DP1.4.

[marcgii]

Is there a way to force a monitor to use only a single head? Until I get a DP2.1 card, I want to use the 5k monitor as a secondary display. Setting the monitor to run in "DP1.1" mode makes it use one display head. But it also fully locks out 5k at all refresh rates. I tried setting a custom resolution with NVCP. But no luck there. In theory I should be able to run 5k60 with a single display head.

[ToastyX]

(07-05-2026 10:05 PM)marcgii Wrote:  Is there a way to force a monitor to use only a single head? Until I get a DP2.1 card, I want to use the 5k monitor as a secondary display. Setting the monitor to run in "DP1.1" mode makes it use one display head. But it also fully locks out 5k at all refresh rates. I tried setting a custom resolution with NVCP. But no luck there. In theory I should be able to run 5k60 with a single display head.

Yes, the workaround is at the top of the first post:

(09-07-2012 09:06 PM)ToastyX Wrote:  Use RegEdit to disable using multiple heads, but the pixel clock will be limited to the single-head limit:
Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\#### (usually 0000)
Value: "EnableTiledDisplay"=dword:00000000

[marcgii]

Thanks. Is there anyway to disable it for just one given display?

[ToastyX]

(07-06-2026 11:35 AM)marcgii Wrote:  Thanks. Is there anyway to disable it for just one given display?

No, it's a global setting in the driver.

[moecre]

Hi there,

I'm new to this forum and this is my first post. Thank you for this great resource first of all.

My problem, and hopefully somebody can explain to me what might going on here.

I bought a Blustream Signal Processor (https://www.blustream.co.uk/hdmi-signal-...m11earc-8k) a few month back, since then I've been in touch with their support on a regular basis to make this work. Shout out to Paul, he was very patient and helpful to me!

The setup: PC (Win11+AMD RX 7900 XT) -> SM11EARC-8k -> AORUS CO49DQ display (5120x1440p with max. 144 Hz).

Because of pass-through mode on the SM11 not working, we flashed a custom EDID on the device and the resolution works great BUT I don't get refresh rates higher than 60 Hz. I tried to amend the "detailed resolutions" in the "extensions" section (DisplayID 1.3), same way as we were able to get the 5120x1440 resolution but this does not work with refresh rates.

Has anybody ever experienced something like that?

I'd be grateful for every push in the right direction.

[EDIT]: I should add that the refresh rate of 144 Hz pops up in the selection menu on Pauls testbench but not in my setup. I can't see anything higher than 60 Hz, independent of what I add to the section.

[EDIT]: See the original EDID of the monitor with all detailed resolutions here     . I assumed, if I'd copy them over to the actual EDID flashed onto the devices, these resolutions and refresh rate combinations show up in the display panel, but they don't.

[ToastyX]

(Today 04:48 PM)moecre Wrote:  Hi there,

I'm new to this forum and this is my first post. Thank you for this great resource first of all.

My problem, and hopefully somebody can explain to me what might going on here.

I bought a Blustream Signal Processor (https://www.blustream.co.uk/hdmi-signal-...m11earc-8k) a few month back, since then I've been in touch with their support on a regular basis to make this work. Shout out to Paul, he was very patient and helpful to me!

The setup: PC (Win11+AMD RX 7900 XT) -> SM11EARC-8k -> AORUS CO49DQ display (5120x1440p with max. 144 Hz).

Because of pass-through mode on the SM11 not working, we flashed a custom EDID on the device and the resolution works great BUT I don't get refresh rates higher than 60 Hz. I tried to amend the "detailed resolutions" in the "extensions" section (DisplayID 1.3), same way as we were able to get the 5120x1440 resolution but this does not work with refresh rates.

Has anybody ever experienced something like that?

I'd be grateful for every push in the right direction.

[EDIT]: I should add that the refresh rate of 144 Hz pops up in the selection menu on Pauls testbench but not in my setup. I can't see anything higher than 60 Hz, independent of what I add to the section.

[EDIT]: See the original EDID of the monitor with all detailed resolutions here . I assumed, if I'd copy them over to the actual EDID flashed onto the devices, these resolutions and refresh rate combinations show up in the display panel, but they don't.

Use CRU to export a file and post it here.

[moecre]

(Today 07:13 PM)ToastyX Wrote:  

(Today 04:48 PM)moecre Wrote:  Hi there,

I'm new to this forum and this is my first post. Thank you for this great resource first of all.

My problem, and hopefully somebody can explain to me what might going on here.

I bought a Blustream Signal Processor (https://www.blustream.co.uk/hdmi-signal-...m11earc-8k) a few month back, since then I've been in touch with their support on a regular basis to make this work. Shout out to Paul, he was very patient and helpful to me!

The setup: PC (Win11+AMD RX 7900 XT) -> SM11EARC-8k -> AORUS CO49DQ display (5120x1440p with max. 144 Hz).

Because of pass-through mode on the SM11 not working, we flashed a custom EDID on the device and the resolution works great BUT I don't get refresh rates higher than 60 Hz. I tried to amend the "detailed resolutions" in the "extensions" section (DisplayID 1.3), same way as we were able to get the 5120x1440 resolution but this does not work with refresh rates.

Has anybody ever experienced something like that?

I'd be grateful for every push in the right direction.

[EDIT]: I should add that the refresh rate of 144 Hz pops up in the selection menu on Pauls testbench but not in my setup. I can't see anything higher than 60 Hz, independent of what I add to the section.

[EDIT]: See the original EDID of the monitor with all detailed resolutions here . I assumed, if I'd copy them over to the actual EDID flashed onto the devices, these resolutions and refresh rate combinations show up in the display panel, but they don't.

Use CRU to export a file and post it here.

Thank you, here you go:

- The original EDID of the monitor connected via HDMI directly and exported:
  AORUS CO49DQ.bin (Size: 384 bytes / Downloads: 2)
- The EDID I got from Blustream to make the 5120x1440 resolution work, through the signal processor:
  5120x1440P EDID.bin (Size: 256 bytes / Downloads: 1)
- The EDID, with 144 Hz based on the one provided by Blustream. Doesn't matter what refresh rate I add here, it stays on 50 Hz:
  5120x1440 EDID 144.bin (Size: 256 bytes / Downloads: 1)

I hope this helps!

[katates]

Hi everyone, I have two screens connected to my 4090 latest driver yesterday.

One is LG C9 on 4k@120Hz over HDMI 2.1 and the other one is LS49 (Odyssey Neo G9 Miniled) 5120x1440@240Hz (DSC).

Basically I switch between these two regularly, at most 1 screen is enabled the other is basically off. I used multiple monitor switch tools (DisplayFusion, MonitorSwitcher etc.) also switching manually. Going to LG C9 is always fine.

When switching to G9 60Hz always works. But when I directly switch to 240Hz it basically freezes all the time, completely until I reboot. (SSH to desktop works btw).

As a solution I tried switching to 60Hz first waiting couple of seconds then running Enable-PnpDevice & Disable-PnpDevice then switching to 240Hz. So this kinda works maybe %60 or so. But still its nowhere near what I would call ok.

I digged through some pages and some posts on Google but I couldn't find any solution. I saw couple mentions that its related with some Nvidia DSC bug. Is there any proper solution that can be achieved with CRU or some other way?