Considering vram when preparing for a triple-monitor gaming build

I'm planning on building a gaming rig to use either Nvidia Surround or Eyefinity in a 3 monitor 5760x1080 or 7680x1600 resolution display, and I'm hoping that the cards I end up putting into it will last me for quite a few years with at least adequate performance in games long down the road (not necessarily maxed out).

n researching, one thing I've heard is that high resolution gaming like that tends to run into bottleneck issues with a graphics card's memory. I've been a long time Nvidia customer, and I've always been satisfied with their cards, however I'm concerned with the fact that they always trail behind AMD in the memory department. Even this article seems to hint that Nvidia is (yet again) going to be a full gigabyte of vram behind AMD on their Kepler reference cards.

Is the concern of becoming bottlenecked by limited card memory in the next few years legitimate enough for me to defer to trying my hand with a pair of AMD cards? Or is my understanding of those implications somehow lacking?

The VRAM concern is a very real one. As it stands today there isn't a single gpu on the planet that can max BF3 with AA at eyefinity resolutions. Even the 7970 with its 3GB buffer chokes. As more and more games start to support super high resolution textures this problem is only going to grow.

Adding cards does not help as the VRAM is not cumulatively added. 1 7970 or 4, doesn't matter there is still only 3GB VRAM available.

edit: ^^^ Thanks Swifty, I will check that out when I get a chance.

Memory is mirrored in SLI and Crossfire, not stacked. Two 2GB cards in SLI have a combined total of 2GB functioning vram

Does anyone have any inkling about what sort of memory buffer is going to be necessary for Surround gaming for a few years?

If the 3 monitor gaming build needs more than 3GB, he can always wait until there is a 6gb 7970 or nvidia alternative release.