Custom Resolution Utility (CRU)

[DragonRulerX]

(01-24-2024 02:36 AM)ToastyX Wrote:  

(01-23-2024 01:44 PM)DragonRulerX Wrote:  Hi

I've been fighting with my new monitors for awhile now and the more I research things the more I'm getting confused. I was told about this CRU tool in the Monitor Enthusiasts Discord. This tool seems very feature rich and possibly able to fix my issue, but a lot of the terminology in the UI is going over my head. I'm hoping someone can help me fix the issue I'm having.

Setup:
I'm running an RTX 4090 FE currently with 3x Cooler Master Tempest GP27U monitors on Win11 Pro.

Problem:
My understanding about how the RTX 4090 FE works is that it basically turns off ports when it detects DSC so it has more processing power to perform DSC. The RTX 4090 FE comes with 3x DP 1.4a + 1x HDMI 2.1a ports. Therefore, if I have 2x monitors claiming they can use DSC then that's technically all 4 ports "in use". This makes the 3rd monitor "inactive" but, still detected by Windows. In order to get the 3rd monitor to work I'd need 2x or 3x of the GP27U's to not use DSC and 1x or 0x of the GP27U's to use DSC. I've read that some monitors have a method to basically turn off DSC by changing their DisplayPort "version" from 1.4 to 1.2 or something, but this kind of configuration option does not appear to exist in the GP27U's OSD menu nor in any Windows settings screen nor the NVIDIA Control Panel screen from what I can tell. I've even tried buying different DisplayPort "version" cables before I learned that DisplayPort "versions" are kind of misleading and not intended to be used to identify capabilities of cables/ports etc as per the DisplayPort wiki (which is a totally separate thing breaking my brain).

What I've done:
In my ignorance I've contacted NVIDIA who claim they aren't responsible for providing an option to control DSC, apparently, and that Cooler Master would need provide a firmware update to enable this option in the OSD. So, I contacted Cooler Master and frankly they've completely ignored me in all avenues of communication (Discord, Support Tickets, and phone). As a last ditch effort I reached out on the aforementioned Discord server which lead me here. I've tried doing some research on how to use CRU, but I'm pretty lost because I've not kept up on the monitor market in a long time.

I understand some of the nuance surrounding DSC's automatic behavior enough to at least mildly understand why there isn't just an explicit option in CRU labeled "DSC: On/Off", but since I don't understand the rest of the settings by their given names too well I'm incapable of easily figuring out what settings need to change to get this configuration to work. Sadly, I have until the end of this month to get this figured out basically due when I bought these monitors and if I'm going to need to return the monitors or not.

Goal:
Max out the specs of one monitor (4K @ 160Hz w/HDR etc) and have 2x 4K @ 60Hz monitors.

Any help would be super appreciated!

DSC should only be active for resolutions that require it, so if you set the other two monitors to 3840x2160 @ 60 Hz, then DSC shouldn't be active on those monitors.

I did try that before posting here, but it didn't work. The GP27U is very strange when you look at its history and current feature set. It really doesn't like to play nice with multiple monitors. Unfortunately, I haven't been able to contact the vendor so any specific questions I have such as the one I'm posing here can only be answered by what is in the manual - which isn't very comprehensive.

A really interesting and strange behavior is how the inactive monitor loses its settings randomly sometimes too. I can make edits in the NVIDIA Control Panel to a given monitor, change the set of 2 currently active monitors to a different pair and make changes there, followed by returning to the original pair and find my settings reverted back to factory on the monitor that was deactivated during the transition over to the other set of 2 monitors.

Ex: (A->A*, B, !C), (!A, B, C->C*), (A, B, !C) instead of (A*, B, !C)

The experience with the monitor has actually been very frustrating regarding configuration. I'll keep it for awhile longer while I wait for a new purchase of other undecided brand monitors to arrive so I still want to try to find a fix to this to post somewhere for posterity, but I have actually found monitors that explicitly declare in their manuals DisplayPort "version" / DSC On/Off controls so I'm intending to purchase a set of them after I get the response from one last vendor who didn't list these controls in their manual to make my final decision.