RT working in CPU not GPU

[Daytona]

Recently I had to reinstall my system and currently Vray RT works only in CPU mode. When I launch it in GPU mode the active shade window freezes on 'waiting for image data' and a windows window pops up with an information that vray stand alone has crashed, trying to find a solution .... (something along those lines).
I'm using windows 7 x64 with 285.62 drivers for my 470 gtx card.

I have previously used RT with the same card and everything worked fine. Do you think it might just be a matter of different drivers?

Thanks

[Alan Iglesias]

Do a C-Drive search for the file *.clbin (usually in a Temp directory), delete it, and then re-install the nVidia drivers. Hopefully that will get you going...

-Alan

[Daytona]

Thanks Alan, but I didn't find any file with such an extension. I uninstalled completly the drivers and installed them again with the same result (vray RT hangs and still no .clbin file by the way).

Should I try with an earlier version of the drivers ?

[Daytona]

i went back and installed the 260.99 drivers which I have been using previously with Vray RT and the exact same video card and this time it worked.But the drivers are about a year old. Is there any way to find out which ones will work properly. Anyone using more recent ones with gtf 470 ?

[Alan Iglesias]

Good to see that you are up and running.

I am also using drivers which are quite old. In my experience, the even older ones (that I cannot use anymore with the GTX580) were like 10%-20% faster! This being said, it will be nice when the newest drivers are not only working for all the cards, but also at optimum OpenCL speed and compatibility.

We have an update coming next month, and I think I heard that at least some of these driver issues will be addressed then. But when you consider that A, that the Chaos Group and nVidia have to work together constantly to keep all of this up to date and running well (a process, no doubt), and B, that OpenCL is "riding" atop CUDA in our case, it isn't surprising that it is taking some time.

I'm hoping to see some real strides taken in 2012. Lately I have been working on a character-based project that is most often rendered using exterior views. Because of the lack of noise in these renderings due to using fewer lights and not having to deal with "interior" shadows and such, I am finding that I can render these shots completely with the GPU. It is simply incredible to be not only very fast but also be completely free of all the image quality vs. speed biasing that we are all so used to doing! Not only that, but because of the progressive nature of PPT, the texture mapping can be so much better looking without all the filtering and other compromises.

There is absolutely no doubt that GPU rendering will be a huge part of my future working in 3D.

-Alan

[vlado]

To give you some more information about the driver issue, the problem is that one of the OpenCL compiler options changed between the different nVidia driver releases and newer drivers do not accept the option that worked for older drivers. Rather than simply ignoring it, the OpenCL compiler simply stops. It's such a trivial issue, but I guess things like that are not altogether unexpected. If anyone is having issues with this, please email us to vray@chaosgroup.com and our support guys will get you an updated build.

Best regards,
Vlado

[Alan Iglesias]

Thanks for the info, Vlado. Much appreciated...

-Alan

[Daytona]

Thanks for all the answers. I still have a problem with RT and Max performance overall ... the older drivers (260.99) work with Vray RT, but Max viewport performance slows down significantly. For some reason it's not a problem with more complex geometry, but it takes a second or two to just 'draw' the GUI for editable poly for example. So it makes Max completely unusable.

I guess I'll just install the latest drivers (285.62 I guess, or the 285.79 beta) and send e-mail to support.

@Alan
I also have high hopes with RT ... so far a couple of minor issues make it just a nice tool for previews and so far I'm not using it for production (yet). Support for procedural textures (like fallof), correct color mapping/gamma (one that would always match the results from Advanced version), alpha channel would behave exactly like the CPU version or render elements support ... those are the things I'd like to see some day.

[Daytona]

Just want to say that the 285.79 beta actually works.
Once again thanks for all the help.

[RobPhoboS]

I'm definitely having lots of issues but I'm not on the nightly builds & using Maya (if that makes any difference). I don't think I can use the GPU with my version

[vlado]

It might be better to wait for the next official update in December then.

Best regards,
Vlado

[RobPhoboS]

It might be better to wait for the next official update in December then.

Best regards,
Vlado

Yep that's my plan for now.
A little frustrating but hopefully it'll be working in the update. Plus for now I've got to do some MR stuff for classes (boo).

[Alan Iglesias]

@Alan
I also have high hopes with RT ...

I understand that I am a bit lucky right now to have jobs that happen to let me use RT/GPU for final work. Most folks up here are doing stuff that really demands some missing traditional features and the stuff you ask for makes a lot of sense. It wouldn't surprise me if many of these issues are resolved relatively soon...just about the time the one might buy a metric crapload of GPU cores for a very reasonable price!

Looking forward to it...

-Alan

[Daytona]

for some reason it stopped working again. No changes to vray, Max or display drivers. :/

Is there any log file that would help figure out what causes vray RT to crash on GPU ?

[vlado]

If you look at the V-Ray RT render server console window, it should give at least some hints.

Best regards,
Vlado