bignastyid :
For SLI you mainly just need to make sure they use the model of gpu and have the same vram. The clock speeds and manufacture don't need to match.
https://forums.geforce.com/default/topic/469402/
Awesome! Thanks for the clarification.
Kinda off topic, but i see that you have the setup i'm looking to get. How has it worked for you?
It seems kepler has been neglected by nvidia lately. Witcher 3 in particular.