Screen Glitch During RT GPU

[PDI]

Whilst using RT for Gpu, the screen begins to flicker after about 3min. The flickering does not stop until I restart. I am using a Quadro Fx 580 with latest drivers.

See image attached.

[vlado]

The -5 error in the RT render server window means that the OpenCL driver has run out of resources. Can you show me the rest of the console window (where it says the line numbers)? You can try reducing the ray bundle size/rays per pixel a bit and see if it helps.

Best regards,
Vlado

[PDI]

I will try to get the whole console window next time. I tried reducing the Ray Bundle size and rays per pixel. 128 and 16 respectively seems to work well.
I think my graphics card is too underpowered to run dual monitor and vray rt gpu. I am trying to distrubute to another two machines with little success. Is vray rt gpu able to distribute the work load to other machines?

[vlado]

Yes, distributed rendering works fine here - in fact, V-Ray RT always uses distributed rendering, even when doing a local render. However keep in mind that you must have a device (a monitor or dummy plug or whatever) plugged into the render slave video card, otherwise Windows will just turn it off. The only cards from nVidia that can work without a monitor attached are the Tesla cards.

Best regards,
Vlado

[PDI]

This is the error I get when I distribute render using RT with GPu.

[vlado]

Ah, ok. Are you able to do a local render on that machine? What card and drivers does it have? Does the CPU engine work?

Best regards,
Vlado

[PDI]

It's an nvidia geforcefx 9800gt with latest drivers.
It doesn't seem to be working with cpu either. Keeps says scene empty and the New Data Index is 0. Then it just hangs.

[vlado]

Ok; are the V-Ray RT builds on the client and the server the same?

Best regards,
Vlado

[PDI]

I re-intalled Rt on the server and it's working!

[vlado]

Ah, there you are then Good to know.

Best regards,
Vlado

[PDI]

Will there be a possiblity in a future version of Rt to have a hybrid model that uses both Cpu and Gpu?

[Alan Iglesias]

You could, but it would significantly slow down the GPU rendering...

It may be cool though, to eventualy be able to distribute different frames in an animation to CPUs as well as GPUs so you could use both without the CPUs slowing down the GPUs...

-Alan

[vlado]

You can do it even now, but I don't really recommend it, as there might be differences when you use features that are supported in one engine, but not in the other. In any case, if you wish to try, you can create an environment variable called VRAY_OPENCL_MIXED_MODE from the System applet in the control panel and give it a value of "1" without the quotes. Then V-Ray will attempt to run the CPU and the GPU engines independently and in parallel. If you give it a value of "2", only the intersection will be done on the GPU, and the shading will be CPU. Both are very experimental and we haven't really tested them much.

You will need to re-start the V-Ray RT render server for the change to take effect.

Best regards,
Vlado

[PDI]

Is Gpu rendering ever going to be used for production rendering in normal Vray?

[vlado]

That depends in part on the feedback from the beta for V-Ray RT GPU

Best regards,
Vlado