TANE and Nvidia SLI


I'm asking this question again because the last time it was asked was about a year before TANE was released with Tony and Windy not knowing alot of stuff and I'd like to know where we're at right now.

There is some information which we simply don't have yet, because it will depend on what happens when the engine meets the full-blown Trainz content set.

Locally, a new 1070 costs over SGD600 while just today I saw a nice 4GB Gigabyte GTX770 for 180 which would pair up great with the identical one I already have.
Anyone with identical (same chip and VRAM) SLI setups can share their experiences running TANE? AMD Crossfire users feel free to chip in too.