That's what I though regarding the Vram issue, so I guess the other 2gb is system reserved for the overhead? Seems I'll be shopping for 4gb Nvidia's.....wasted alot of money with ATI 7950's prior and won't return that side for awhile, unless they have markedly better 4k performance.
I don't run FPS or twitch games, more strategy or some mmorpg's, so crazy fps isn't the goal. The Seiki 39" I have will only push 30hz at 2160p, damned HDMI 1.4 limitation, no 2.0 yet and no displayport either. It does run 1080p@120hz though, for those games that run better that way
Still the main question remains, Is a gtx670 bottlenecked by a 8x Pci-E 2.0 pipe? Or would SLI at 16x/16x be preferable to Tri-Sli at 8x/8x/8x on a PCI-e 2.0 board?
My intuition seems to say the SLI route is the way to go, kinda found similar running Tri-3D or Tri-120hz at 1080p, but that video grade refresh rate does add in a different element. In Neverwinter for instance, even though the refresh is capped, I still get in the mid 40's with 3 cards. I think I'll pull the 3rd one this weekend and see for myself what the difference is on just the games I play, but the engineer in me is still wondering about the numbers of it all.
By no means am I displeased with the current setup, just a question of optimization and power consumption.