NVidia is who designed the chipset in the first place... eVGA mostly just slaps a label on the card, but they didn't engineer it.
It's like owning a car... all things being free (as drivers are), would you rather take your Porsche 911 to be worked-on by a Porsche dealership, or would you take it to Bubba's autoshop?
NVidia designed the thing, they manufactured the chipsets... you think they would make the best drivers.
Go referance drivers... which always means directly from Nvidia in this case. (As an example, some respected companies like BFG who themselves sell these cards even tell you to use NVidia's drivers because they are the best).