GTX Titan SLI vs GTX Titan X

For rendering, consider the memory of a titan x; it has more, and only one card's memory will be used.

Look for reliable benchmarks of the render engine you are planning on using, then it's a matter of balancing render speeds against scenes that will take up more memory than the titans that have 6GB v the titan x with 12GB.

If a lot of your scenes are above 6GB then you won't benefit from a titan black as it wont fit in its memory. So even if it turns out to be faster on scenes that fit on both cards, of it doesn't get used due to memory constraints it's a waste of cash.
 
For the price, I'd consider the Gigabyte G1 Gaming 980ti instead of the TitanX. With a nice OC it gives TitanX performance levels in gaming for substantially less cost.

Also MUCH cooler and quieter, even with the OC.

Skip to 5:00 for benchmarks.

Ref:
[video="https://www.youtube.com/watch?v=B2-gCXscH04"][/video]
 


Well, I was offered to trade my 295x2 for the Titan X, but I could also sell my 295x2 and buy 2 Titans. I need them for the CUDA stuff as I mentioned.
 


Certainly if the memory isn't a requirement then it is a compelling argument, but for those using it for rendering the extra memory may be critical.