Fixing the DCH driver stalls

[bo3bber]

That transition to DCH introduced the weird stalls in the control panel. Microsoft forced Nvidia to repackage the driver DCH style, and NVidia broke the 3D Driver settings as part of that transition. One of our friends of 3D is madshi, who makes a cool 3D TV output device and relies upon 3D Vision for his frame-packed 3D for 3D movies. He and I managed to work out what was happening with that DCH transition.

(One interesting tidbit from him is that the DX11 output path for frame-packed, not frame-sequential, video still works. So 3D TV Play seems to still work on latest drivers. If you can install it.)


Now for the gritty details- If you find the two x32 and x64 components in the 3D Vision folder, and then copy them into the proper location in the system32/driverstore, then it revives the 3D Vision service and everything goes back to normal.

Two files: nvstapisvr.dll and nvstapisvr64.dll from the root of a 3D Vision driver install. Unzip the .exe if needed. I can't remember if these need the driver version patched or not, but just use 3DFM/HelixVision to update the driver and use the Drivers->StereoscopicDriver->Win10 path.

Copy those files into the correct location for them at:
C:\Windows\System32\DriverStore\FileRepository\nv_dispig.inf_amd64_647b4244e991951b\Display.NvContainer\plugins\LocalSystem

Your hash code for inf_amd64 might very well be different, it changes for every driver. Just be sure it's the NVidia driver.

That's where NVidia control panel plugins go for the new DCH layout. You need to take ownership of that folder, and it's non-trivial to get access there, but once you drop the files in, that's it. Probably a good idea to reboot, but after that DCH drivers act the same as Standard.


If someone can work out the easiest/best way to take ownership of that protected system folder, please let us know. Everytime I do this I can never understand it, but still seem to get it to work.

[3DNovice]

Wagnardsoft may very well have what you need (DDU authur)
He has/had a tool called Take Control

Edit: oops, no wonder I couldn't find it, it's called GMP (Give Me Power)
https://www.wagnardsoft.com/forums/viewtopic.php?t=5 About
https://www.wagnardsoft.com/forums/viewtopic.php?t=6 Download

You could probably talk to him, if it doesn't do everything you want

The original thread on it, prior to his official site
https://www.nvidia.com/en-us/geforce/fo ... ed-061914/

[3DNovice]

He also has TDR Manipulator, perhaps it might be useful for something

Why Freeze or hang? because the TDR feature of Windows job is to reset the videocard driver if the Windows TDR process detect that something jammed on the GPU for too long. (this is a noob friendly explanation)
For more details, refer to : http://msdn.microsoft.com/en-us/library ... s.85).aspx

TDR is a "watchdog" (Timeout Detection and Recovery of GPUs ) present since Windows Vista. If it detect that the card is taking too much time to execute something of that it feel that the GPU is in a frozen state (This is a noob friendly explanation) that the TDR will reset the GPU or some part of it (since windows 8) in an attempt to not leave the computer in a frozen state.

[3DNovice]

I saw this from Manuel, I've no idea what NGX is, but perhaps it useful.

3y
Sorry for the late reply. This is expected behavior. In general, the way DCH drivers are packaged and installed differs from Standard drivers. As far as NGX components, it gets installed to the DriverStore.

There is a funny/old/obsolete named pipe that NVidia uses for communication to 3D. We don't understand the details, but we did find out that under DCH drivers the service that runs that pipe gets installed to the wrong locaction, because it was not updated for the new install locations. This is on NVidia- the 3D Driver was still supported during that time, and they did nothing to make it work properly on DCH.

I wouldn't be surprised if this is what was acquired from their acquisition of 3DFX and simply never changed since.

[EpsilonLyrae]

Edit: Redundant speculative post. Would delete it if I could.

[3DNovice]

Intel released an unlocked DCH driver to bypass OEM restrictions, perhaps something useful can be gleaned there to resolve an issue


https://www.ghacks.net/2020/04/28/intel ... ver-locks/
https://community.intel.com/t5/Graphics ... d-p/695354

[RAGEdemon]

Copy those files into the correct location for them at:
C:\Windows\System32\DriverStore\FileRepository\nv_dispig.inf_amd64_647b4244e991951b\Display.NvContainer\plugins\LocalSystem

Another data point:

My folder location is different:
C:\Windows\System32\DriverStore\FileRepository\nv_dispig.inf_amd64_c0e159863e7afdde\Display.NvContainer\plugins\LocalSystem

Taking ownership [via https://www.howtogeek.com/howto/windows ... -in-vista/] and pasting the 2 files, then rebooting, does not change Control Panel behaviour, i.e. it doesn't seem to work. 3D driver has been injected and works in games via geo-11 otherwise.

Also, 3DFM/HelixVision does not seem to allow driver updates past 452.06



and

just use 3DFM/HelixVision to update the driver and use the Drivers->StereoscopicDriver->Win10 path.

There is no such path...


Suggestions appreciated...

[EpsilonLyrae]

OK I think I just figured something out. I'm not sure I copied over the correct dll files, though...

You probably have to be logged into an admin account. Navigate to C:\Windows\System32\DriverStore\FileRepository then look for a folder that starts with nvdisp. The exact name of your folder here will depend on your installed driver version and possibly other factors such as which version of Windows exactly that you're on. I had two, because I did an in-place upgrade of my driver without using DDU. If you have more than one, the "date modified" field for most of the contents inside should be close to, or an exact match for the date that the driver version you're using released on. In my case, I'm on 516.59, which released 06/28/22. Most of the contents of my folder were modified on 06/23 or 06/24.

Right click LocalSystem, go to properties. Security tab, then click advanced. At the top, it'll say that SYSTEM is the owner. If you're on an admin account, you can click Change and you'll be allowed to modify this field. In the new window that pops up, type the name of your windows account, then click OK. Apply, OK, then OK again to close the properties for the folder. Open them again. Security tab, advanced, change permissions. Click add. At the top, click "Select a principal". Type in the name of your windows user account here. Now you can change the basic permissions for this folder. Check the "Write" box, OK, Apply - Pay attention to the warning here, you are giving your account permission to write into a system directory where driver files are loaded from. Only copy over or change things here when instructed to do so by someone you trust, using driver files from a source that you trust. Click Yes, OK, OK.

Now, when you navigate into the LocalSystem folder, you can put any files you want inside. When you have copied the correct .dll files over, I strongly recommend you reverse the entire process - remove your account from the list of users with permissions, then change ownership of the folder back to SYSTEM. You may get some prompts that say it couldn't modify permissions on individual files, ignore this. Once you're off the list and SYSTEM is the owner, you will no longer be able to modify the contents of the folder. You definitely do not want your user-level account to have 24/7 access to this folder, anything could silently write to it or change things without your knowledge otherwise.

In my case, when I went to C:\Program Files (x86)\NVIDIA Corporation\3D Vision and copied nvStereoApil.dll / nvStereoApil64.dll over to the driver store folder and rebooted, it did not result in a meaningful change. Perhaps I copied the wrong dll files over?

[Dazzawill]

I tried with just the 2 DLLs specified but had no success. I then did it by putting all the DLLs from the 3DVision install directory to the System directory specified above and it worked. After that I deleted all the streaming related DLLs and gave ownership back to the system, rebooted and its still working fine. So it does appear we need more than just those 2 DLLs mentioned.

[bo3bber]

OK, strange. This is why I didn't post this earlier, not sure we have all the details. Worked in my 47x.xx driver, but have not tried on 5xx.xx drivers. Might have changed, might be something else I do that I don't remember setting up.

BTW, we also drop in an extra file as part of the 3DFM 3D setup, that was also lost as part of the DCH conversion. That file is "Resource.dat", and was part of Standard drivers, but removed in DCH. It goes into "C:\ProgramData\NVIDIA". Not sure this is required, but maybe. It is installed automatically by 3DFM/HelixVision when you install the 3DV driver.


If you don't use 3D Vision, you don't need this of course. If you do need 3D Vision, use the installer from 3DFM/HV at the top of the Drivers tab. The 3D Vision Driver is NOT the Nvidia Video Driver. It needs to be numerically patched to match whatever Video Driver you have installed, which is what the top button does.

Once it's patched and installed, the Drivers folder in 3DFM/HV will have an unpacked and patched version of the 3D Vision Driver. That's the easiest place to fetch the files, and they are known good, and Nvidia files.

[EpsilonLyrae]

I tried with just the 2 DLLs specified but had no success. I then did it by putting all the DLLs from the 3DVision install directory to the System directory specified above and it worked. After that I deleted all the streaming related DLLs and gave ownership back to the system, rebooted and its still working fine. So it does appear we need more than just those 2 DLLs mentioned.

This intrigued me. I took a slightly less all-in-one approach here.

In the end, from the 3dfixmanager folder, I copied the following dlls to the driverstore folder:

nvStereoApiI.dll, nvStereoApiI64.dll (rebooted, nothing changed)
NvSCPAPI.dll, NvSCPAPI64.dll (rebooted, nothing changed) <-- These are listed as "Nvidia 3D Vision Control Panel API" in their details)
nvstapisvr.dll, nvstapisvr64.dll - Change was apparent as soon as I closed my current instance of the Nvidia control panel and re-opened it. A system reboot or GPU driver reboot using CRU was not required on 516.59 (These are listed as "Stereo Vision Control Panel API Server Plugin" in their details)

I don't have the patience to test the minimum viable setup out of these 6, but with all of them in the driverstore folder, turning 3d on/off, and accessing any content that initializes the 3d driver is all as responsive as the standard driver now.

[EpsilonLyrae]

This has also had the pleasant side effect of restoring my ability to use the native 3d vision function of taking stereoscopic screenshots, something I was only able to do before while using the standard version of the driver

[RAGEdemon]

Can confirm files needing copied from folder : ...\HelixVision\Drivers\StereoscopicDriver\Win10\NV3DVision\

nvStereoApiI.dll
nvStereoApiI64.dll
nvstapisvr.dll
nvstapisvr64.dll

Reboot also not required for me, though might for some...

Thanks EpsilonLyrae and bo3b.

[bo3bber]

nvstapisvr.dll, nvstapisvr64.dll - Change was apparent as soon as I closed my current instance of the Nvidia control panel and re-opened it. A system reboot or GPU driver reboot using CRU was not required on 516.59 (These are listed as "Stereo Vision Control Panel API Server Plugin" in their details)

I don't have the patience to test the minimum viable setup out of these 6, but with all of them in the driverstore folder, turning 3d on/off, and accessing any content that initializes the 3d driver is all as responsive as the standard driver now.

Excellent. I must have written down the wrong file names. Those are definitely the right ones, because there is some mechanism that makes a 3D Vision server, which creates a named pipe that the CP library calls. That call has been failing, which hits a 5 second timeout. So files named 'svr' are definitely the ones we want.

Thanks all for checking, I'll modify the first post.

At some point we'll want this to be automated by code to take ownership and copy the files, but that'll have to wait for another day.

[john105]

nvstapisvr.dll, nvstapisvr64.dll - Change was apparent as soon as I closed my current instance of the Nvidia control panel and re-opened it. A system reboot or GPU driver reboot using CRU was not required on 516.59 (These are listed as "Stereo Vision Control Panel API Server Plugin" in their details)

I don't have the patience to test the minimum viable setup out of these 6, but with all of them in the driverstore folder, turning 3d on/off, and accessing any content that initializes the 3d driver is all as responsive as the standard driver now.

Excellent. I must have written down the wrong file names. Those are definitely the right ones, because there is some mechanism that makes a 3D Vision server, which creates a named pipe that the CP library calls. That call has been failing, which hits a 5 second timeout. So files named 'svr' are definitely the ones we want.

Thanks all for checking, I'll modify the first post.

At some point we'll want this to be automated by code to take ownership and copy the files, but that'll have to wait for another day.

I can confirm that only nvstapisvr.dll and nvstapisvr64.dll are needed. Thanks bo3b, great find! I also found that it fixes the setup wizard.

[The_Nephilim]

nvstapisvr.dll, nvstapisvr64.dll - Change was apparent as soon as I closed my current instance of the Nvidia control panel and re-opened it. A system reboot or GPU driver reboot using CRU was not required on 516.59 (These are listed as "Stereo Vision Control Panel API Server Plugin" in their details)

I don't have the patience to test the minimum viable setup out of these 6, but with all of them in the driverstore folder, turning 3d on/off, and accessing any content that initializes the 3d driver is all as responsive as the standard driver now.

Excellent. I must have written down the wrong file names. Those are definitely the right ones, because there is some mechanism that makes a 3D Vision server, which creates a named pipe that the CP library calls. That call has been failing, which hits a 5 second timeout. So files named 'svr' are definitely the ones we want.

Thanks all for checking, I'll modify the first post.

At some point we'll want this to be automated by code to take ownership and copy the files, but that'll have to wait for another day.

I can confirm that only nvstapisvr.dll and nvstapisvr64.dll are needed. Thanks bo3b, great find! I also found that it fixes the setup wizard.

Hmmm, I had to put in all 4 dll's? Also I did notice I was also able to run the Setup Wizard.. So what does this do for us in general or is there a bigger picture here I dont get?

[john105]

Hmmm, I had to put in all 4 dll's?

No, only 2 are needed: nvstapisvr.dll and nvstapisvr64.dll.

So what does this do for us in general or is there a bigger picture here I dont get?

It fixes some of the things mentioned under "Issues with DCH driver" in viewtopic.php?p=168475#p168475

[Flint Eastwood]

Does anyone know, why the 3D-Vision Test application (NvStTest.exe) doesn't work anymore with the DCH drivers?
3D-Vision is not triggered. When set Multisample to 2x or 4x the app starts switching between left and right image, but completely random - anyway, the IR-pyramid stays dark.

[3DNovice]

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[3DNovice]

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