970 SLI VRAM questions

It is to my understanding that even though I am using two cards, the VRAM does not stack and stays at 3.5GB. In the games I play, attempting to push high resolutions, I am seeing that this 3.5GB mark is surpassed quickly. Once it goes above that mark, performance is theoretically hindered to the speed of my system memory. So my question is: Will getting faster RAM improve my performance in games that go over 3.5GB of VRAM in any significant way? To my calculations, 2400Mhz Ripjaws X (CL11) should have a lower latency of 9.1ns vs my current Ripjaws 1600Mhz (CL9) latency of 11.25ns. A 18.5% performance increase for the latency. [(CL/Freq-in-MHZ)*1000]= latency in nanoseconds.

Would you guys recommend I purchase new RAM or not worry about it?

Not worry about it. You would be better off getting a card with more vram than system memory.

Okay, is there a way to set a thread as "Answered"?

Solved, yes. I believe it's in thread tools?

on the bright side with the advent of dx12 it will use the memory additively if available (of course the game has to be coded for dx12) so hopefully soon