45 hours + for a render - you are ...
My record so far is 10.5 days (and nights). Of course I ended up having to do it in pieces, so that was the total, but one of the trees alone was something like 5 days and nights.
Of course that was using DS3A in 32-bit (since that’s all there was for the Mac) Not sure how long it would taske on DS4Pro in 64-bit, but it still wouldn’t be quick.
If you really want to seriously kill rendering time, use a bunch of Xfrog trees and plants. The evergreens are especially nasty as Xfrog uses transmaps for all of the needles. Raytracing iterations have to go way up, otherwise you start to get “blocks”. I did a render in Dec2011 containing over a dozen Xfrog evergreens, with some overlapping, in a winter setting. I stopped monitoring it after 2 weeks - 64-bit 3Delight Standalone, 8-cores (Dual Xeons 4 Cores ea), 32 Gb RAM (16 Gb per CPU).
I was using a set of evergreens from RDNA, supposedly fairly low poly, but Hi-res textures. But then since they needed to be *Christmas* trees, I compounded the damage by bunging in the Redhouse Christmas tree, scaling it and turning the tree invisible, to get the balls and tinsel. It’s small wonder it took so long. And there were five of them in the scene. The render times varied from overnight to like I say, something like five days and nights. The room, otoh, even with the figures and their wigs and a couple of holly wreaths and garlands took all of a couple of hours.
It was fairly easy to assemble once I had all the pieces, but gad, getting the pieces…