There are bad and good news to tell you today.
The bad news
is that Dualview is broken in all nVIDIA Graphic drivers starting from 275.33
. This time the problem is not related to the registry settings. It's the driver file itself which just doesn't work correctly. To be more specific, these are the two main driver files:
What's interesting is that if you check their description in all versions of the drivers up to 270.61
(the last where Dualview works) you can see this:
nv4_disp.dll - NVIDIA Compatible Windows 2000 Display driver, Version 270.61
nv4_mini.sys - NVIDIA Compatible Windows 2000 Miniport Driver, Version 270.61
That's right, even though the installer itself doesn't accept Win2k any more, the driver files still seem to be somewhat targeted at 2K/XP.
On the other hand, in drivers 275.33
and newer you've got this:
nv4_disp.dll - NVIDIA Windows XP Display driver, Version 275.33
nv4_mini.sys - NVIDIA Windows XP Miniport Driver, Version 275.33
This is just a description and the newer drivers themselves do work in Win2k too but Dualview does not. The second monitor just doesn't show up in the Display Properties and there's an error when trying to enable Dualview manually. I'm 100% sure that these files are directly responsible for this because I did try to flip the installer INF files between the older and the newer drivers... but unfortunately it made no difference
I also tried to mix different versions of the two files concerned but it only resulted in BSODs. The two seem to be interdependent.
Now it's time for the good news
. The good news is that it's possible to just take even the newest driver (306.81
at the moment) and just replace its nv4_disp.dll & nv4_mini.sys with the ones from 270.61
. This way we end up using an older driver but the rest of the files (CUDA, OpenGL, etc.) are newer and also the INF installer is from the new drivers which means that all new nVIDIA graphic cards are supported! In conclusion, it seems to be possible to use the older driver to keep the Dualview compatibility and still be able to detect all new nVIDIA graphic adapters. Actually, there's also another file directly related to the two main ones called "nvcpl.dll". This file is responsible for the "NVIDIA Display Properties Extension" and its version has to be exactly the same as "nv4_disp.dll" in order to run... but the solution is pretty simple. You just need to manually change the file version and it will work even with the older drivers.
I wonder if there's anyone with a fairly new nVIDIA card willing to test these drivers. Please let me know if you could test them in your system. I myself own only an older GeForce 6600. It's still supported by the new drivers so I am able to test them directly on my computer but I'd just like to be sure that such a modified driver works in case of the new graphic cards too.
Edited by tomasz86, 03 November 2012 - 09:10 AM.