I've been trying out a few things in 3ds max with vray rendering at 1000x600 pixels.
I'm using progressive so that I can get a good idea of what things will look like in the final within 5-30 minutes each render. (I usually just stop it after it reaches several passes)
I have noticed however, whenever I crank up the resolution to anything around 2000 pixels on one side, the render times increase exponentially! I never even make it to the first pass for an entire hour. Is this just how rendering works or could there be an setting I need to change as I increase resolution?
My scene is very simple, 5 walls, a few glass panes, some mulleons, and a large white "endless" backdrop surface. The walls do have a modest 1/2 inch brick displacement on them.
FYI, I am using a single, low end computer (Intel i7 4790k/8 GB Ram) if that may be the cause.
One extra detail I noticed is that when rendering the smaller images, my cpu stays at around 100% usage, while using the larger images it fluctuates between 20-70% ever few sconds.