VRay and IRay don't detect Titan X Cards when GPU Rendering

[padre.ayuso]

I have a new machine that I got with two Titan X cards. I'm running 3DS Max 2013 and have just installed a trial version for 3DS Max 2016 to test these cards.

These cards don't seem to get detected by 3DS Max/VRay/IRay. The solution to use the cards when doing GPU rendering in VRay RT is to unselect In Process RT engine, however that makes both my cards run when I'd like to use one only for interactivity purpose or to leave one rendering going while working on another one with the other card.

 

Has anyone found or know a solution? I tried tweaking the Environment Variables per different threads I found on different forums and I have also tried installing 3 different drivers for the cards to no avail.

 

To solve the problem temporarily, I have just reduced the Ray Bundle Size, but I'd like to be able to just select one GPU when doing this type of work to use the other for graphics work on another scene.

 

Thank you!