Custom Resolution Utility (CRU) Work in Progress

[ToastyX]

It has been a while since CRU has had a major update. I've been working on rewriting CRU from scratch, but it's taking longer than I'd like, so I thought I'd release a work in progress to give advanced users something to play with. Some features have not been reimplemented yet, and it has not been fully tested. This will not be the UI for CRU 2.0. CRU 2.0 will have an easier consolidated mode with a new layout and an advanced mode. This is more like the advanced mode but with the old layout.

Download: cru-test-2026-01.zip

Important differences:

• Descriptors such as "Name" and "Range limits" are now edited from the "Detailed resolutions and descriptors" list in the main window. Use the "Edit..." button under the list and not the button at the top of the window.
• Standard resolution descriptors are no longer added automatically. To add more than 8 standard resolutions, add a "Standard resolutions" descriptor manually, or add a "VTB-EXT" extension block.
• YCbCr 4:2:2/4:4:4 for HDMI is now in the CTA-861 extension block window. For DisplayPort, use the "Edit..." button at the top of the main window.
• "TV resolutions" data block has been renamed to "Video resolutions" to align with CTA terminology.
• Interlaced detailed resolutions vertical timing parameters are now per frame to avoid confusing resolution changes and for consistency with DisplayID. For EDID detailed resolutions, the vertical active resolution, front porch, and sync width must be even, and the back porch, blanking, and total must be odd.
  

Major changes:

• The display list now only contains active displays and inactive displays with overrides
• The "Edit..." button at the top now contains EDID properties such as product identification, display parameters, and color characteristics
• All detailed resolution fields can now be edited (use the triangle button to show all fields)
  • Sync type should always be "Digital separate" even with CRT monitors
  • Borders are only supported by NVIDIA
  • Added OVT standard
    
• All descriptors are now supported
  • Range limits now supports all timing definitions
  • CVT and Established III resolutions are not commonly used and only work with EDID 1.4 (normally used with DisplayPort only)
  • Color point and color management are not commonly used and have no effect in Windows
    
• Extension blocks are now readable with all GPUs including Intel
• Extension block header fields can now be edited
• FreeSync data block HDR profiles can now be edited
• HDMI data block 3D fields can now be edited
• HDR static metadata data block now shows actual luminance values along with the raw values
• New CTA-861 data blocks:
  • G-SYNC
  • HDR dynamic metadata
  • HDR10+
  • Microsoft head-mounted and specialized displays
  • Native video resolution
  • Product information
  • Vendor-specific
  • Video format preference
  • Video format resolutions
    
• New DisplayID data blocks
• VTB extension blocks now support CVT resolutions (not commonly used)
• Import will now always import the complete EDID
• Dark mode is now supported

[intimki]

CRU only works if IOMMU is enabled in the BIOS. Otherwise, Windows simply freezes during the driver initialization phase on the boot screen. How can I fix this? I don't want to have to enable IOMMU all the time
NVIDIA RTX 3080, Driver 596.02

[ToastyX]

(Yesterday 02:16 AM)intimki Wrote:  CRU only works if IOMMU is enabled in the BIOS. Otherwise, Windows simply freezes during the driver initialization phase on the boot screen. How can I fix this? I don't want to have to enable IOMMU all the time
NVIDIA RTX 3080, Driver 596.02

Do you have multiple displays connected? NVIDIA's driver has a bug that can cause Windows to hang during boot when an EDID override is present with multiple displays connected and G-SYNC enabled. There is a workaround using scripts: https://www.monitortests.com/forum/Threa...wn-scripts

[intimki]

(Yesterday 02:54 AM)ToastyX Wrote:  

(Yesterday 02:16 AM)intimki Wrote:  CRU only works if IOMMU is enabled in the BIOS. Otherwise, Windows simply freezes during the driver initialization phase on the boot screen. How can I fix this? I don't want to have to enable IOMMU all the time
NVIDIA RTX 3080, Driver 596.02

Do you have multiple displays connected? NVIDIA's driver has a bug that can cause Windows to hang during boot when an EDID override is present with multiple displays connected and G-SYNC enabled. There is a workaround using scripts: https://www.monitortests.com/forum/Threa...wn-scripts

I actually have two monitors, but I tested various methods with just one connected. It makes absolutely no difference.
In addition, the script, as a general solution, is just a one-time fix. The reason is: reboots, accidental power outages, etc., when the EDID reset won’t have time to take effect. In any case, resetting the EDID won’t help on the next boot unless you apply it in advance every time before shutting down

[ToastyX]

(Yesterday 04:27 AM)intimki Wrote:  I actually have two monitors, but I tested various methods with just one connected. It makes absolutely no difference.
In addition, the script, as a general solution, is just a one-time fix. The reason is: reboots, accidental power outages, etc., when the EDID reset won’t have time to take effect. In any case, resetting the EDID won’t help on the next boot unless you apply it in advance every time before shutting down

This can only be an NVIDIA driver bug. The IOMMU must be preventing the driver from hanging. This must be a new bug because I'm not aware of this happening with a single monitor connected. The workaround includes making a shutdown script, but you can actually reset the EDID immediately after restarting the driver instead. The EDID override will still be in effect as long as the driver doesn't restart.