I currently have a system with 2 x NVIDIA GeForce GTX 980 Ti and am suffering from some pretty annoying render times on some scenes (up to 2.5 hours) and would like to get that down. So am considering the natural progression of putting in 2 x NVIDIA GeForce GTX 1080i Ti.

Basically, I'm trying to work out if it's worth sinking cash into the 1080 or grind my teeth and wait for the next one (1180 I guess?)

I have two questions on this: (a) I assume people have done this here, roughly what kind of realistic render improvement are we looking at? (I know this is pretty subjective based on what you are rendering)

(b) There appear to be lots of different types of 1080Ti cards out there, does anyone have any recommendations or are they pretty much all the same?

Other system stuff if needed: Overclocked Intel i7-5820K Processor Asus X99-A Motherboard 64Gb Ram 2 TB HDD, 7200 / 480 GB SSD

Thanks Lee