Yeah, I'm getting fairly certain that my performance issue has something to do with something linked to the Tatra with a bed and motion. I don't know what it is, but it happens most of the time, but not every time, and stops when the Tatra is parked. This does not seem to happen with the one without a bed.
I'm not really having any luck finding more consistent details.
I make a road, spawn the Tatra with bed and move it, and my framerate drops to 15. But not every time...
At first I was wondering if it depended on the time of day (and how much of the 3D grass the shadow was hitting), but that doesn't seem to be it either. Maybe my GPU IS running out of memory? Maybe I'll check to see if I can find a good program to see what it's doing with my GPU and see if there's anything odd.
I used to have RivaTuner, but that stopped being updated in 2009. Any suggestions?
Edit: Just quickly tried GPU-Z, and just running Outerra nearly maxes out my GPU memory and GPU load with no framerate issues. That's not very helpful...