Waiting for image data

[Steveph23]

Hi

I have a Z68 Motherboard with GTX Titan installed. I was able to use Vray RT with Vray 3 up until I added an extra card, a GTX 650 Ti, they both use the same Driver.

The Titan would load the scene in under a minute but now it just sits on the 'Waiting for image data'. The driver does not crash it just sits on waiting.

I can get RT to work on a very simple model but as soon as it becomes large with textures it just grinds to a halt.
I have tried setting my 'choose OpenCL devices to Titan and to 650 and both, and the same issues happens.

I know the scene worked with the Titan so I'm not sure why it doesnt work now.

Any help or advice would be appreciated. I have also adjusted the performance settings in RT to see if anything changes.

Thanks

Steve

[savage309]

The CUDA mode will work better on Nvidia GPUs. Are you using it or OpenCL ?

[Steveph23]

Using CUDA, does that mean changing the OpenCL has no bearing on just using the titan for RT and the other for viewport?

[savage309]

You can choose the RT Engine from RT settings tab (for NVidia GPUs it is highly recommended to use CUDA since it will be faster). There is a tool that is coming with V-Ray installation ocldeviceselect - using it you can choose what GPUs to be used for V-Ray RT GPU (restart of Max/Maya required in order changes to applied), so you can use 1 of the GPUs for the viewport and the other for RT (the one that has monitor plugged in is aways used for the viewport).

You should be able to use both of them for RT too, if you like. When you start RT GPU, V-Ray console application that contains all the log from the RT execution is started. When a problem occurs, it might help to give a screenshot of it or just see if there is something suspicious (650 may be out of memory, or may be the driver didn't find it, or something else, hard to tell without more information).

Btw, what is your OS, driver version, and are you using Max or Maya ?

[Steveph23]

I am using max 2013 windows 7 pro and driver 335.23, I don't have many textures in the scene so I am not sure the graphics card is running out of memory. When I get back on the machine tomorrow I will have a look at the log and see if there is anything suspicious! Thanks for your advice so far.