HTC VIVE with 2 Nvidia TITAN X

[Anonymous]

Hello gents,

Someone knows if there is a proper graphics configuration for using HTC Vive with VRED and 2 Nvidia TITAN X?

I have tried with both SLI options in Preferences--Render Options--Visualization Advanced but is not working properly. When i switch to only one graphic cards it works perfectly.

I adjoin an example of what I am seeing. Thank you in advance,

Regards.

[michael_nikelsky]

For VR you have to use the multicast Stereo SLI option, alternate frame does not work for VR (don´t forget to restart VRED after changing the setting, this can´t be changed during runtime). It should work just fine using two TitanX, at least on SLI certified gaming motherboards, I am not sure if SLI with gaming GPUs works correctly on workstation motherboards, you might need Quadro cards for those. 

[Anonymous]

You tried 

EDIT > PREFRENCES > VISUALISATION ADVANCED > SLI > MULTICAST STEREO and it doesn't work?

Strange, are you sure SLI is enabled in your nvidia settings when you right click on the windows desktop?

[Anonymous]

Good morning, thank you for your answers,

Michael: Yes we are using the multicast stereo SLI option, and yes I have restarted not only VRED but also the computer several times and still not working. I checked the motherboard yesterday and it its certified.

Jaker: Yes we have the SLI enabled in the NVidia settings, that's the strange thing. With only one graphic card is working good but the moment we enable the SLI the problem starts.

Thank you again for your help, I'm running out of ideas.

[michael_nikelsky]

I am a bit confused about the image you have posted. It does not look like it is in the Vive-Rendering Mode at all, looks more like a normal stereo rendering of some sort to me.

Which driver version are you using? We require at least version 361.91 although I would recommend the 364.72 driver or newer.

Also (due to nvidia´s great naming concept): Are we talking about the Maxwell based Titan X cards or about the Pascal based Titan X cards? We have not been able to test the Pascal based gaming cards yet, only the Quadro P6000 is known to work.

[Anonymous]

Thank you for the quick reply.

The image I posted is just an example to show more or less what I'm seeing through the VIVE glasses, basically an unsinchronized image between the two eyes. I'm not allowed to post anything related with the project I'm working on.

We are using the Driver version 372.7. The graphic cards are TITAN X PASCAL.

Regards.

[Number-Seven]

Hello folks,

I'm experiencing exactly the same issues I have two titan-x and an ASUS Z10PE-W8 with dual processors and latest drivers/firmware is installed. I'm using the multicast Stereo mode.

When the SLI option is activated in the Nvidia controls. I see two separated pictures stuttering while moving in the VIVE.

It seems that the stutter doesn't come from low fps, as the picture on screen is perfectly fluent and not separated on both eyes.

Also when i close one eye in the VIVE i see the separation.

When i turn of the SLI in the nvidia controls everything is working fine, just not so fast.

If it helps i could do a video with the mobile through the VIVE, so you see the problem.

cheers,

marcel

[michael_nikelsky]

Sounds like a driver issue to me. I have just tested it with two Quadro M5000 and I do know that it works with two Quadro P6000 since we just showcased them at GTC Europe so mostlikely there is something broken in the drivers for the Titan XP.

[Number-Seven]

everything else is working in VR, even the "waiting room" before i see the VRED scene.

And when I'm in the scene i see the "Fence" on the floor which is overlayed by SteamVR.

The background image and the "Fence" is working fine, its just all the geometry in the scene which has this effect as described previously.

[Anonymous]

Same problem for me number-seven, waiting room is working fine. I have even tried with different software that supports VR and its working perfectly.

Thank you for your answers.

Regards

[michael_nikelsky]

In the preferences, can you turn on MainWindow->Show FPS in Statusbar and check the framerates you get with one and with two GPUs?

For the Vive, anything below 90fps will show these double images which basically means your scene is to complex for VR.

You can try calling setOpenVRHMDForceInterleavedReprojection(true) which will force the framerate to 45 fps and reproject every second frame.

[Anonymous]

Good morning,

At the beginning we thought that was because of the scene complexity but turns out that if we try with an empty scene with one sphere happens the same.

I have tried also with the code line but is not helping.

If someone have any new ideas I will be much appreciated.

Regards!

[Anonymous]

Hi all,

I've got the same setup and also running in the same problem. Some news on this topic already?

Thanks and regards!

[michael_nikelsky]

Nvidia is aware of the issue but at the moment it is unknown what causes the problems. It most likely is related to the mainboard in some way but I don´t know if it is hardware, a driver or a bios issue.

The only thing I can´t stress enough is to make absolutely sure that both GPUs are using a PCIE slot connected to the same CPU in a multi CPU system. Other wise data has to pass the QPI which is too slow. Also getting the latest drivers and bios updates might be a good idea.

[Anonymous]

Hello All,

I would like to help you regarding to SLI problem as same as mine right now. (2x) geforce gtx 980.

Couple weeks ago according to answers about this topic (https://forums.autodesk.com/t5/vred-forum/vred-2017-vr-interaction-performance-and-interact-issues/t...SLI was working great until when i installed this win update: https://www.microsoft.com/en-us/download/details.aspx?id=36805

I installed this update because of this issue for another software for stereoscopic images display for htc vive: https://plus.google.com/113778585718610353084/posts/11oa5HjQRKH?fscid=z12yj5czumm2ws2kkxvyfd5zfwyagu...

As @Anonymous says `With only one graphic card is working good but the moment we enable the SLI the problem starts.` exactly it`s happening to me after update.. %50 fps drop down when i try to activate SLI.

I hope someone can solve this issue with that hints..

Thank you and Best Regards

[michael_nikelsky]

That is a very interesting find, thanks a lot.

Kind regards

Michael

[lbs_markus_s]

Any News on that?  currently i'm having the same issues with two Titan XP!!

[michael_nikelsky]

We were not able to reproduce this issue on our systems. The most likely causes for the SLI issues with the Vive are usually:

- CPU with to few PCIE-Lanes (you need at least 32-PCIE-Lanes, otherwise performance will be bad)

- wrong Slot in a Dual CPU board

- Bad enumeration of the cards, meaning the display is connected to what the driver sees as the second GPU, causing everything to be copied twice

- SLI mode in VRED is not set to multicast SLI

- Scenetrees that are too deep

- Too many expensive calls in the script

The last two are also valid when running a single GPU.

[lbs_markus_s]

Hi,

i'm using a i9-7900x with 44 lanes

The vive is connected to the same graphic card as the Monitor.  Both connected to the first one. Even the other way around it does not change anything

sli in the preferences is on.

Difference between the other System with two 1080ti .. when in Switch to open vr mode i get no message in the terminal that sli is enabled

[michael_nikelsky]

If you don´t get that message then there is probably something broken in the driver. If you start VRED with the -console flag you should see the number of Multicast SLI GPUs VRED initializes.

You can also try to manually set the environment variable for multicast SLI in Windows:

GL_NV_GPU_MULTICAST=1

Kind regards

Michael