Hi Jair Gal and forum, I am currently going through the same thing. I realized rendering times were going up ridiculously, in our newest workstation. This might be a problem with these newer vray updates that tend to throttle the cpu (around 30% permanent usage) with certain map combinations. I ticked "override materials" and found CPU went back to 100% usage while rendering. I then started excluding, one by one, each material to see which ones were causing the problem. I ended up isolating a couple of materials that use rather HiRes maps for diffuse, reflection, glossiness and bump (like a shiny wall cover), and tried turning on each map separately. They only cause the problem when they are all switched on at the same time. This is rather intriguing, not to mention annoying. The specs are a 4770k with 16Gb Ram, and should be more than ok to handle these kind of simple interior scenes.
Still can't figure out how to make the materials to work the same way I have always made them. But at least I found the source of my problem. If anyone finds out what to do in these cases, we are gonna be really grateful.
Good luck and keep posting! I am sure we must not be the only ones with this problem.
Juan.
