Here is the driver that DVI Dual-Link ALREADY works with:

GeForce ForceWare 185.20 (Dated December 26, 2008).

And here is the previous version of the driver, with which the image is NOT YET:

GeForce Forceware 182.52 (Dated April 30, 2009).

I managed to find out that INF has no effect (You can take INF from one driver and add it to another, the result will not change).

Has anyone mentioned powerstrip yet? Maybe it can help?

@DoZator

You linked to an XP driver not a 98 driver, are you running XP or 98?

Dualboot Windows 98 & Windows XP.

I am now trying to fix DVI Dual-Link with old drivers (<185.20) first under Windows XP to understand the reason. The next step is to apply the found solution to earlier drivers for Windows 98 (ForceWare 77.72 and 82.69 for Win9x). The goal is to make DVI Dual-Link work under Windows 98 (not just Windows XP or higher) with native monitor modes (1920x1080@120Hz or higher).

Sphere478 wrote on 2022-10-28, 15:45:

Has anyone mentioned powerstrip yet? Maybe it can help?

What specifically needs to be done with powerstrip?

DoZator wrote on 2022-10-28, 15:11:

Here is the driver that DVI Dual-Link ALREADY works with: […]
Show full quote

Here is the driver that DVI Dual-Link ALREADY works with:

GeForce ForceWare 185.20 (Dated December 26, 2008).

And here is the previous version of the driver, with which the image is NOT YET:

GeForce Forceware 182.52 (Dated April 30, 2009).

I managed to find out that INF has no effect (You can take INF from one driver and add it to another, the result will not change).

What could have changed in the 185.20 driver, compared to the previous ones, that it now began to detect a monitor connected via DVI Dual-Link and display a normal image?

So, I tried playing around with the modes in PowerStrip and I was able to set some previously unavailable modes and resolutions on a dual link DVI cable, connected according to darry's recipe. Such modes, for example, as 1024x768@120hz or 1600x900@100hz or 1920x1080@100hz (With some font distortions) or 1920x1080@75hz (Without distortions) could be set, but at the same time, for example, with 1600x900@100hz the monitor writes, they say "Not correct cable. Use the dual link DVI cable that came with the monitor." Accordingly, since the cable is exactly the one you need and works flawlessly in Windows XP with GeForce ForceWare 185.20 or higher drivers, in full dual-channel mode, we can confidently say that the video card does not switch to dual-channel mode under Windows 98 when using the method, suggested by darry on the previous page.

It turns out that the video card initially, even at startup, produces the correct DVI Dual-Link signal, but for some reason the monitor does not understand it, showing a black screen. At the same time, the GeForce ForceWare 185.20 (From 2008) or higher driver switches the video card to another DVI Dual-Link output mode, which modern monitors already understand. To get around this difference and use a modern monitor under Windows 98 (For which there is no driver newer than 2006, 82.69), it was suggested above to try options with hardware converters and EDID emulators, but is there a simpler option, without the need for additional hardware? Well, like, for example, modifying the VBIOS of video cards in the likeness of modern ones (Which already at the BIOS stage issue the required DVI Dual-Link signal), or maybe in Windows 98 somehow override the original EDID with the correct one? What else is it possible to try to do?

Does the Windows 98 driver have that Nvidia CP like these days where you can create custom modes?

DoZator wrote on 2022-11-04, 02:10:

So, I tried playing around with the modes in PowerStrip and I was able to set some previously unavailable modes and resolutions on a dual link DVI cable, connected according to darry's recipe. Such modes, for example, as 1024x768@120hz or 1600x900@100hz or 1920x1080@100hz (With some font distortions) or 1920x1080@75hz (Without distortions) could be set, but at the same time, for example, with 1600x900@100hz the monitor writes, they say "Not correct cable. Use the dual link DVI cable that came with the monitor." Accordingly, since the cable is exactly the one you need and works flawlessly in Windows XP with GeForce ForceWare 185.20 or higher drivers, in full dual-channel mode, we can confidently say that the video card does not switch to dual-channel mode under Windows 98 when using the method, suggested by darry on the previous page.

It turns out that the video card initially, even at startup, produces the correct DVI Dual-Link signal, but for some reason the monitor does not understand it, showing a black screen. At the same time, the GeForce ForceWare 185.20 (From 2008) or higher driver switches the video card to another DVI Dual-Link output mode, which modern monitors already understand. To get around this difference and use a modern monitor under Windows 98 (For which there is no driver newer than 2006, 82.69), it was suggested above to try options with hardware converters and EDID emulators, but is there a simpler option, without the need for additional hardware? Well, like, for example, modifying the VBIOS of video cards in the likeness of modern ones (Which already at the BIOS stage issue the required DVI Dual-Link signal), or maybe in Windows 98 somehow override the original EDID with the correct one? What else is it possible to try to do?

I would really like to suggest something helpful, but I'm out of both ideas and practical experience (I have never owned a DVI dual-link equipped monitor nor have I ever tried to run >165MHz resolutions over HDMI or DP on any Windows version older than 10 or maybe 7 ).

darry wrote on 2022-10-25, 18:41:

DoZator wrote on 2022-10-25, 18:37:

darry wrote on 2022-10-25, 18:15:

Maybe the old Nvidia driver is trying to push wacky timings with huge blanking intervals that exceed even 330MHz by default .

This is also possible, but the problem starts earlier - a black screen immediately after turning on the PC, even at the boot stage. Which confirms your assumption about the absence of the necessary BIOS EDID information in the video card. Or even in the monitor itself.

That's not necessarily a big problem, as it could be overcome with an EDID emulator (are there ones with dual-link passthrough support, or otherwise need to modify build your own) or maybe a dual-link to DP converter with a programmable EDID.

EDIT : If you've got spare cash and time, this might be worth a try https://www.amazon.com/Gefen-GTV-DVIDL-2-MDP- … r/dp/B01LZT2Z15 . According to some reviews, it is more flexible than official specs let on, but still might not help at all, depending on what is actually causing the issue in your case .

It is worth paying attention to the following things. This converter converts the DVI Dual-Link signal coming from the graphics card to "Mini DisplayPort". Thus, to connect to a monitor with a DVI Dual-Link input (Without any DP, which in my case), you will also need a converter back from Mini DisplayPort to DVI Dual-Link.

I also paid attention to the following characteristics of this converter - "Advanced EDID Management: Mode 1: 2560x1600, Mode 2: 2560x1440, Mode 3: EDID pass-through"

Mode 3: EDID pass-through - this, apparently, will be transmitted to the monitor what the video card still produces (the Monitor does not understand this).
Mode 2: 2560x1440 and Mode 1: 2560x1600 - the monitor is also unlikely to understand, because its ceiling is 1920x1080.

As I understand it, initially the GeForce 7950GT outputs something similar via DVI Dual-Link (2560x1440 or 2560x1600), assuming that a high-resolution monitor is connected, it scales the source signal at the hardware level (For example, at the BIOS and MS-DOS boot stage) up to higher the specified permissions. Naturally, the monitor rejects such a signal (For it is designed for 1920x1080).

In modern video cards, support for 1920x1080 in DVI Dual-Link mode has already been added at the VBIOS level, so there are no such problems. On older video cards, such support is provided by the video driver (I would like to figure out what it changes there).

Thus, if you rely on converters to DisplayPort and vice versa, it seems that, in addition to the converters themselves, you will also need to scale from the original signal 2560x1440 or 2560x1600, which the video card produces by default, to 1920x1080.

However, this way seems to me still not ideal (Even in the case of implementation), since it certainly imposes additional output delays. I would still prefer the option of modifying the VBIOS of the video card to output 1920x1080 initially, instead of 2560x1440 or 2560x1600 when connected via DVI Dual-Link.

Are there any experts on modifying the VBIOS of retro video cards? Could you suggest something about this?

I never meant to imply that https://www.amazon.com/Gefen-GTV-DVIDL-2-MDP- … r/dp/B01LZT2Z15 was a sure thing in your use case, far from it.
Based solely on official disclosed specs, it likely would not have done anything useful. However, reading some of the comments on it suggested it could do more than official specs implied (not that it necessarily would have helped you).
Moreover, I also missed the fact that you have a XL2411 , not the XL2411P (which also has DP input). Sorry about that .

That being said, I am not at all convinced that a patched vBIOS would help with getting 1920x1080@144Hz working under Windows 98, as it isn't necessary for Windows XP . My guess is the XP driver is just more flexible/better. I could be wrong, of course .

EDIT :
Anyway, my current line of thinking regarding that Gefen gizmo is that it might be possible to boot your system with it while having the vBIOS "think" that a proper dual-link 2560x1440 monitor is connected at boot into Windows 98's DOS (who care's if there's no picture at this point), then switch the EDID to passthrough and then finally start Windows 98 .

It might work, it might not and the fact that this thing costs 200$ and that a DP to DVI dual-link converter would also be required (and possibly have its own issues/limitations), makes this an expensive gamble, IMHO .

It was generally possible to fix the DVI port by using the usual "Single-Link" digital EDID from the HDMI port of the same monitor (With some modifications). The original EDID, with which the image does not work, contains, for example, the following data:

Established Timings I & II:
IBM : 720x400 70.081663 Hz 9:5 31.467 kHz 28.320000 MHz
DMT 0x04: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
DMT 0x06: 640x480 75.000000 Hz 4:3 37.500 kHz 31.500000 MHz
DMT 0x09: 800x600 60.316541 Hz 4:3 37.879 kHz 40.000000 MHz
DMT 0x0b: 800x600 75.000000 Hz 4:3 46.875 kHz 49.500000 MHz
Apple : 832x624 74.551266 Hz 4:3 49.726 kHz 57.284000 MHz
DMT 0x10: 1024x768 60.003840 Hz 4:3 48.363 kHz 65.000000 MHz
DMT 0x12: 1024x768 75.028582 Hz 4:3 60.023 kHz 78.750000 MHz
DMT 0x24: 1280x1024 75.024675 Hz 5:4 79.976 kHz 135.000000 MHz
Apple : 1152x870 75.061550 Hz 192:145 68.681 kHz 100.000000 MHz
Standard Timings:
DMT 0x52: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz
GTF : 800x600 119.999886 Hz 4:3 77.160 kHz 83.950000 MHz
GTF : 1024x768 119.999931 Hz 4:3 98.760 kHz 139.054000 MHz
DMT 0x23: 1280x1024 60.019740 Hz 5:4 63.981 kHz 108.000000 MHz
GTF : 1280x1024 120.000185 Hz 5:4 131.640 kHz 233.793000 MHz
GTF : 1440x900 119.999896 Hz 16:10 115.800 kHz 229.747000 MHz
GTF : 640x480 119.999084 Hz 4:3 61.800 kHz 52.406000 MHz
Detailed Timing Descriptors:
DTD 1: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (531 mm x 298 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 4 Vsync 5 Vback 36 Vpol P
Display Product Serial Number: ...
Display Range Limits:
Monitor ranges (GTF): 56-144 Hz V, 30-160 kHz H, max dotclock 330 MHz

Detailed Timing Descriptors:
DTD 2: 1920x1080 99.930409 Hz 16:9 113.221 kHz 235.500000 MHz (531 mm x 298 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 5 Vback 45 Vpol N
DTD 3: 1920x1080 119.982181 Hz 16:9 137.260 kHz 285.500000 MHz (531 mm x 298 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 5 Vback 56 Vpol N
DTD 4: 1920x1080 144.000765 Hz 16:9 158.113 kHz 325.080000 MHz (531 mm x 298 mm)
Hfront 24 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 5 Vback 10 Vpol P

And the video card apparently cannot provide this initially (vBIOS cannot do this yet). The newer XP driver from 2008 already does this, so the video card used Dual-Link after entering XP. And the Windows 98 driver from 2005 naturally cannot do anything like that. I associate this problem with the widespread adoption around 2008 of LCD monitors for 3D Stereo, with support for 120Hz. Apparently, just for their normal support, the vBIOS of video cards was redesigned.. And for old cards they made a fix in the driver. And Windows 98 did not receive this fix. Therefore, the monitor cannot negotiate with the video card, which believes that the EDID is broken and turns off the signal. Video BIOS is not friendly with this EDID.

Hence the idea to try to find a monitor with DVI Dual-Link support, released BEFORE this whole story with the introduction of 120hz 3D to the masses. And this is approximately 2005 +\- 12 months. If you find such a monitor, you can try to take the EDID from it. At least the video card will work with it. Well, and most importantly, it will provide a two-channel connection that understands both vBIOS and ForceWare 77.72. And then you can try to modify it, gradually increasing the frequencies, setting the correct resolutions.

But where can I find a list of all DVI Dual-Link monitors of that time from among those that are in the EDID database?

DoZator wrote on 2022-10-28, 20:31:

Dualboot Windows 98 & Windows XP. […]
Show full quote

Dualboot Windows 98 & Windows XP.

I am now trying to fix DVI Dual-Link with old drivers (<185.20) first under Windows XP to understand the reason. The next step is to apply the found solution to earlier drivers for Windows 98 (ForceWare 77.72 and 82.69 for Win9x). The goal is to make DVI Dual-Link work under Windows 98 (not just Windows XP or higher) with native monitor modes (1920x1080@120Hz or higher).

Sphere478 wrote on 2022-10-28, 15:45:

Has anyone mentioned powerstrip yet? Maybe it can help?

What specifically needs to be done with powerstrip?

DoZator wrote on 2022-10-28, 15:11:

Here is the driver that DVI Dual-Link ALREADY works with: […]
Show full quote

Here is the driver that DVI Dual-Link ALREADY works with:

GeForce ForceWare 185.20 (Dated December 26, 2008).

And here is the previous version of the driver, with which the image is NOT YET:

GeForce Forceware 182.52 (Dated April 30, 2009).

I managed to find out that INF has no effect (You can take INF from one driver and add it to another, the result will not change).

What could have changed in the 185.20 driver, compared to the previous ones, that it now began to detect a monitor connected via DVI Dual-Link and display a normal image?

If I recall correctly you can use it to make custom resolutions and refresh rates

This stage has already been passed and everything that could be squeezed out of Single-Link seems to have been squeezed out now.
It remains to try to start a Dual-Link, which would overcome the limits of Single-Link capabilities.
But to do this, you need to find a monitor with a DVI Dual-Link connection from the early 2000s (Up to 2006 release approximately), in order to remove the compatible EDID from it, with which the video card driver for Windows 98 from 2005 release can work.

However, I have already found one of these monitors:

Apple Cinema Display HD 30 (M9179)

The description of which, in particular, just indicates the compatibility requirement:

Mac Pro compatibility All new Mac Pro systems support two Apple Cinema Displays, including dual‑link DVI for one 30‑inch model. […]
Show full quote

Mac Pro compatibility
All new Mac Pro systems support two Apple Cinema Displays, including dual‑link DVI for one
30‑inch model. Support for two 30‑inch Apple Cinema HD Displays requires two dual‑link DVI
ports — available in configurations with either the ATI Radeon X1900 XT or the NVIDIA Quadro
FX 4500 — or by installing an additional NVIDIA GeForce 7300 GT card. Support for more than
two displays requires installation of one or more additional NVIDIA GeForce 7300GT cards.

Power Mac G5 compatibility
Any new dual‑ or quad‑core Power Mac G5 supports two Apple Cinema Displays, including
dual‑link DVI for one 30‑inch model. Support for two 30‑inch Apple Cinema HD Displays
requires two dual‑link DVI ports, available in configurations with the NVIDIA Quadro FX 4500
or by installing an additional NVIDIA GeForce 6600 card. Support for more than two displays
requires installation of one or more additional NVIDIA GeForce 6600 cards

The NVIDIA GeForce 6600 is one of the first nVidia cards in the sixth series to officially support Dual-Link.

NVIDIA Quadro FX 4500 - I currently use it, which means that when connecting such a monitor, there should be no problems, in theory. It remains to find the EDID from it and you can try it.