Looking through these sites and some say the EDID registry fix does work to disable 126. I tried for testing above and it didn't so mabye newer drivers broke that method or I put something in incorrectly.
https://forums.tomshardware.com/threads/nvidi … estion.2908350/
https://web.archive.org/web/20120320224631/ht … een_or_text.htm
https://hardforum.com/threads/nvidia-edid-fix … 37w3se.1231737/
https://forums.laptopvideo2go.com/topic/17770 … ing-edid-tweak/

and again with revisiting stuff I've already done....

For DP to HDMI on XP at 2560x1440 @60hz without scaling
https://www.amazon.com/gp/product/B082C7BHK8/ … 0?ie=UTF8&psc=1

Knowing what I know now if I use this and either zeroing out 126 on the monitor or potentially through the EDID emulator or the Nvidia override key if it works then this may be a solution which would allow scaling and limit the monitor to 60hz on a 144hz monitor without the black screen issue of trying to use the higher refresh rates and without having to use refreshlock. Geesh.

No go with DVI to displayport. The cable works but 1024x768 res before boot just like with HDMI on this monitor and Nvidia detects as HDMI. Only DP to DP or DP to HDMI with active adapter results in 2560x1440 on bootup.

Somehow using the EDID emulator messed up my DP to HDMI active adapter so waiting for another one to come in then can look into zeroing 126 on the monitor or the Nvidia driver so that scaling works with this adapter. Since adapter limits refresh to 60hz then no black screens.
For DP to DP definetly need refreshlock for those games that don't honor the set refresh rate and try to use the highest refresh rate the monitor supports. No need to do anything with 126 for this monitor since it's detected as a monitor and scaling works with 355.98 BUT I still need to test the latest nvidia drivers to verify if scaling stops working and if so zero 126.
https://forums.extremeoverclocking.com/showth … ad.php?t=310242

I was also thinking about 4k...
So to sumarize, am I correct that under WinXP it is not possible to get 3840 x 2160 higher than 30Hz on any available videocard?
I read that nvidia drivers are crippled to support only HBR1 mode on DP output (while GPU itself support HBR2 but it works only in Win7+ and Linux) so this imply 30Hz limit, same as for HDMI 1.4. Anybody made some hack? How about ATI cards? Or how complex would be port HBR2 support code from nouveau driver to XP?

I've only been able to get 30hz at 3840x1600.
In my humble opinion it's a driver limitation so the driver needs patched for those pixel clocks, I haven't investigated patching the driver except for emailing Tal Aloni but he scrapped the patching he did after using an active adapter so he was happy with that.
It's definetly possibly that different drivers have different limitations but don't know if anyone has done the legwork, my last AMD card was years ago and the non-Nvidia cards I do have wouldn't be worth using in XP.
As for using open source Linux driver code for Windows it sure would be nice but I haven't seen any interest except for people who have been hacking around with using files from other Windows OS or the leaked Windows source code.

In this article http://wp.xin.at/archives/5616 he also tried 3840x1600 but noted that
"For a 4K/UHD monitor, 3840×2160@30Hz might work" that seems to me logical if you fit into HBR1 limit, of course there may be another obstacle preventing select this resolution but HBR1 bandwidth seems to be unbreakable limit...

ignore previous for this the one program I was using stated 126 in the GUI for some reason, use bits 127 and 128. Zero 127 increment 128 by 1. So if 01 then 00 if C1 then C2.
Although I disabling 126 would disable the second page anyway....

Played around a bit with EDID again in registry, monitor inf and overridedEDID values, again no luck.
EDID in monitor, hardware EDID emulator or modifying the nvidia driver are best bet for looking into getting this to work in the future.
Looks like the EDID in my monitor is read only, had no luck changing this with software, would appear to write but then error out on verifying.
Can't find any displayport hardware EDID emulators. There was the displayport detective but can't find those anymore.
If you read the Nvidia Release notes they do mention how for monitors and TVs that have issues they update the driver for those typically making HDTVs show up as DVI which gets them to work but of course disables HD audio, so easiest route would be to fake your monitor to the EDID of those monitors or HDTVs.

Done for now with testing until next time:
Current config is DVI to DVI (1920x1200 @ 60hz) to one monitor and Displayport to Displayport (2560x1440 @85hz) to another both with scaling using the 355.98 driver.
Using Refreshlock for the 2560x1440 monitor to limit refresh rate to usable values on this XB271HU to eliminate black screen issue.
The displayport to HDMI active adapter does work to eliminate black screens since it's limited to 60hz at 2560x1440 but no scaling available so another potential option would be for a programmable active adapter or EDID emulator that can change the bit or switch to DVI but AFAIK it needs to be active throughout the chain so if using a EDID emulator then it needs to be active.

Forgot, one of the features of the Quadro cards is the ability to load EDID from a file in the Nvidia Control panel so if anyone has a Quadro they want to use in XP then that would be a good test for modifying the bits to disable audio or using an edid that the nvidia driver has set as not HDTV.

Need to look into the registry for EDID change again since this page mentioned XP 64bit, I doubt he'd mention it if it didn't work BUT this was for an ancient Nvidia driver version:
https://www.nvidia.com/en-us/geforce/forums/d … onnection-or-f/

Ran across this: https://analogbit.com/software/edid-disable-exts/
Thought this was interesting so it seems to prove that it wasn't just the Windows drivers that have the the issue and the the issue is definetly a Nvidia driver issue:

"This utility modified a binary EDID file and disables EDID extensions and updates the checksum. This can be used as an override for nVidia’s linux drivers that assume your monitor is a TV."

Need to find an EDID device where you can disable the extensions and need to test on HDMI,displayport. Don't think I had any luck with the one I tested previously but it's possible I messed up.

Something else to look into is to which file or files changed between 355.98 and the next version (358.50?) that broke scaling.
http://us.download.nvidia.com/Windows/358.50/ … lease-notes.pdf
http://uk.download.nvidia.com/Windows/358.50/ … lease-notes.pdf

nv4_disp.dll
nv4_mini.sys
nvapi.dll
nvdata.dat
nvencoderapi.dll
nvinfo.pb
nvoglnt.dll

Files in NvCplSetupInt.exe may be something to look at too

got myself an BenQ EX3210R. Windows xp is being a PITA wrt to 1600x1200 resolution. Its not an option on settings, using a gtx 960 2gb, limited to 1280x1024. Trying to get GOG games on xp to play nice but having to use windows 10 gtx 970 to get 1600x1200 @ 165hz

gmaverick2k wrote on 2022-09-11, 08:59:

got myself an BenQ EX3210R. Windows xp is being a PITA wrt to 1600x1200 resolution. Its not an option on settings, using a gtx 960 2gb, limited to 1280x1024. Trying to get GOG games on xp to play nice but having to use windows 10 gtx 970 to get 1600x1200 @ 165hz

And what connection did you use? HDMI or DP? There must be some stupid thing, no reason why it should not run at least on full HD...

RayeR wrote on 2022-09-12, 18:58:

gmaverick2k wrote on 2022-09-11, 08:59:

got myself an BenQ EX3210R. Windows xp is being a PITA wrt to 1600x1200 resolution. Its not an option on settings, using a gtx 960 2gb, limited to 1280x1024. Trying to get GOG games on xp to play nice but having to use windows 10 gtx 970 to get 1600x1200 @ 165hz

And what connection did you use? HDMI or DP? There must be some stupid thing, no reason why it should not run at least on full HD...

tried both to no avail, 1600x900 is shown then skips 1600x1200... just odd, wanted all the eye candy and buttery smooth at 1600x1200 using this monitor with tech getting close to crt experience (21" crt etc). windows 10 plays nicely whic beats the object of getting EAX etc that windows xp offers. Philscomputerlabs showcased the EX3203R for windows 98 build at 144Hz, but my geforce 5900xt isn't playing nice after taking out the ati 9700 pro. I think it may be because i'm using a passive DVI to HDMI on the 5900xt. i'll keep tinkering when i have the time...

StarTech.com DVI to DisplayPort Adapter - USB Power - 1920 x 1200 - DVI to DisplayPort Converter - Video Adapter - DVI-D to DP (DVI2DP2)
https://www.amazon.co.uk/StarTech-com-DVI-Dis … r/dp/B077FYJTDL
^Was wondering if the above will allow for high refresh rate 1600x1200. anyone know? it says its single link DVI in the description for windows 98 on the geforce 5900xt
also tried on my x800 pci-e ASRock PC, it gimped out... The voodoo 3 2000 PC is defunct with only VGA connector... i need to find a sweet spot that will work with this monitor

VGA works too :

gmaverick2k wrote on 2022-09-12, 20:34:

StarTech.com DVI to DisplayPort Adapter - USB Power - 1920 x 1200 - DVI to DisplayPort Converter - Video Adapter - DVI-D to DP ( […]
Show full quote

StarTech.com DVI to DisplayPort Adapter - USB Power - 1920 x 1200 - DVI to DisplayPort Converter - Video Adapter - DVI-D to DP (DVI2DP2)
https://www.amazon.co.uk/StarTech-com-DVI-Dis … r/dp/B077FYJTDL
^Was wondering if the above will allow for high refresh rate 1600x1200. anyone know? it says its single link DVI in the description for windows 98 on the geforce 5900xt
also tried on my x800 pci-e ASRock PC, it gimped out... The voodoo 3 2000 PC is defunct with only VGA connector... i need to find a sweet spot that will work with this monitor

On modern GPUs (like GTX 960) with 358 driver, on DVI to Display Port you only will get Downsampled "fake" resolutions, and refresh rates are locked to 60Hz (regardless of setting). Also, limited to 16:9 stuff (like HDMI), with failed and/or fake 4:3, 5:4 and 16:10 resolutions.

agent_x007 wrote on 2022-09-12, 22:19:

gmaverick2k wrote on 2022-09-12, 20:34:

StarTech.com DVI to DisplayPort Adapter - USB Power - 1920 x 1200 - DVI to DisplayPort Converter - Video Adapter - DVI-D to DP ( […]
Show full quote

StarTech.com DVI to DisplayPort Adapter - USB Power - 1920 x 1200 - DVI to DisplayPort Converter - Video Adapter - DVI-D to DP (DVI2DP2)
https://www.amazon.co.uk/StarTech-com-DVI-Dis … r/dp/B077FYJTDL
^Was wondering if the above will allow for high refresh rate 1600x1200. anyone know? it says its single link DVI in the description for windows 98 on the geforce 5900xt
also tried on my x800 pci-e ASRock PC, it gimped out... The voodoo 3 2000 PC is defunct with only VGA connector... i need to find a sweet spot that will work with this monitor

On modern GPUs (like GTX 960) with 358 driver, on DVI to Display Port you only will get Downsampled "fake" resolutions, and refresh rates are locked to 60Hz (regardless of setting). Also, limited to 16:9 stuff (like HDMI), with failed and/or fake 4:3, 5:4 and 16:10 resolutions.

i see, that sucks. shame my monitor doesnt have vga connector

gmaverick2k wrote on 2022-09-12, 20:26:

RayeR wrote on 2022-09-12, 18:58:

gmaverick2k wrote on 2022-09-11, 08:59:

got myself an BenQ EX3210R. Windows xp is being a PITA wrt to 1600x1200 resolution. Its not an option on settings, using a gtx 960 2gb, limited to 1280x1024. Trying to get GOG games on xp to play nice but having to use windows 10 gtx 970 to get 1600x1200 @ 165hz

And what connection did you use? HDMI or DP? There must be some stupid thing, no reason why it should not run at least on full HD...

tried both to no avail, 1600x900 is shown then skips 1600x1200... just odd, wanted all the eye candy and buttery smooth at 1600x1200 using this monitor with tech getting close to crt experience (21" crt etc). windows 10 plays nicely whic beats the object of getting EAX etc that windows xp offers. Philscomputerlabs showcased the EX3203R for windows 98 build at 144Hz, but my geforce 5900xt isn't playing nice after taking out the ati 9700 pro. I think it may be because i'm using a passive DVI to HDMI on the 5900xt. i'll keep tinkering when i have the time...

1080p gimps out with HDMI cable, but using DP its fine

gmaverick2k wrote on 2022-09-14, 05:57:

i see, that sucks. shame my monitor doesnt have vga connector

Well, my LG also doesn't have it. I use Aten VC160A as converter from VGA (or DVI-I on GPU), to DVI-D and from that I either use passive adapter to HDMI or active one to DP. In case of my VGA pic from previous post, I used passive DVI to HDMI adapter and HDMI port on my monitor.

running at 1600x1200 @120hz via displayport using customise cvt-reduced blank.
will this mess up my monitor in the long run?

customised 640x480, 800x600 and 1024x768 to run at 165hz. oh my... caesar 3 at 100% speed setting, the people glide across. only ever experienced this on a sony cpd round bottom bezel crt with front joystick i had years ago 😀 joy

Has there been any further progress with this? The best I have been able to do in XP with my 760 is 2560x1440@60. I had to use an active DP to HDMI cable to even get that . I tried a DVI-D to HDMI and could get 2560 but it looked terrible. It only looked ok at 1920. There is a good article on this below.

http://wp.xin.at/archives/5616

In one of the comments a user mentions hex editing some of the driver files to allow HDMI 1.4a bandwidth but I have not tried it yer. I don't have a lot of experience hex editing although I've done it a few times. Does anyone feel like trying it? I can live with 2560 @ 60 because it looks very crisp with this cable, but would like to get closer to 120 if it is possible. I did try some custom resolutions and even though it would pass at 100hz when I try to switch to it the monitor loses the input.