Quote - Well, that's 8 gigs in Carrara.  Exporting that scene through a translator to Octane might optimize things a bit.  Do we know for sure that Carrara's management of scene assets is as efficient as it could be?  Looks like some geometry in that scene could be instanced to save mem if you really wanted to, but all in all, you'd also get a higher quality of render than you have there, in less time.  I'm not knocking your render quality, it's a nice work, but there's a lot of occlusion shadows and atmosphere missing there, which I'm assuming was done to speed up render time.  Also, if you exported that geometry as an OBJ, is the size of the OBJ 8gigs?  Couldn't you reduce bitmap size to help memory too?

OK, so I spend 2 to 3 days figuring-out how to reduce the size of the scene so it renders in Octane?

At this rate I'd much rather use full GI in Carrara, which will 'only' take 24 hours or so to render.

And then what if I want to create a 100 frames animation with this scene? Do I have to adjust all of the frames, one by one? It could literally take me weeks to do it.

If I have Embree implemented in Carrara, this same scene could render in about 1 hour/frame with full GI and much better quality, so in about 100 hours, maybe 150 hours, I will get my animation done.