Unable to communicate with display driver

Steven-V

I have had this happen a number of times on long, moderate to high-res renders... Everything seems fine, CPU load is < 50%, GPU load is in the 90s, rendering is chugging along. Then when it finishes, I get an error message "Unable to communicate with display driver" and DAZ crashes/closes. Of course I lose the render, wasting sometimes as much as a couple of hours of my time.

I don't think the machine is running out of RAM (since RAM is not pegged during the render), so I am not sure what the story is. Sometimes I can render just fine, and sometimes it crashes. In some cases this happened when the screen saver kicked in, but today, I made sure that did not happen and it still crashed.

Anyone know what is going on with this and why it might be happening?

mjc1016

Which renderer?

And is this a laptop or desktop? What OS/version?

Steven-V

Iray. Never had a problem in 3DL.

It's a laptop... high end MSI Dominator, 24 GB RAM, 8 GB VRAM 980M vid card. Win 8.1.

Yeah, I know it's a laptop but still, something this beefy shouldn't crash on an 1800x900 render.

namffuak

I've run into this, and I thought I saw a note somewhere that it was fixed in one of the RC updates.

Basically, the Iray render is stepping on the openGL function on the video card and when the render finishes the Nvidia driver looks around, says "oops" and dies. You might try updating the video driver, but no guarantees.

Steven-V

I updated the driver very recently, but I will check and see if there is another iteration of it.

mjc1016

It can also happen if your sleep/hibernate times are getting invoked...Windows does a pretty poor job of keeping track of what's actually running, so some very long processes can 'get lost' in the shuffle. If it was happening when the screensaver kicked in, then it could happen when one of the other timers expires, too.

I used to have problems like that when I was adding my wife's and and daughter's laptops as Luxrender nodes, but since it was just one node, it didn't kill the whole render, just crash Luxrender on that laptop.

For laptops, I basically set the timers to 'never' for the 'plugged in' profile and that solved the problem for Luxrender.

Steven-V

I know how bad it can be to have power saving modes kick in during a simulation. I run computer simulation models for a living. I had more than one model run killed by a damn screen saver in the 1990s... so I am usually pretty on top of it.

I don't think one of the timers had kicked in the last time it happened, because I was purposely jiggling the mouse every few minutes (I was doing stuff in another room) to prevent that from happening.