I had some questions about a new build I'm considering, but hadn't gotten much in terms of input. I had some questions about the video situation, and figured you guys could give me some advice.

For comparison sake, my current build is this:
i7 2600K
Radeon HD 5850
OCZ Vertex3 120 GB SSD + 2 1TB WDC storage
16GB Corsair Vengeance
3 24" displays

For all intents and purposes, it's great; however, I've decided that for once I actually wanna build a PC that represents the latest and greatest if even just for a month or two.

I don't know much about the 7990 other than it maybe/maybe not be debuted in a month or so, and I know that the 690s are out (but apparently in limited supply?), and they're awesome.

I've never SLIed anything, but I figured if I was going to make some badass computer, that I should have badass videocards to go with it. So, I'm considering a pair of 690s.

I have some questions/concerns, though:

  • To those who have done this before (built a system with the latest and greatest), was it worth it? Is your system still performing exceedingly well 2, 3, 4+ years in? Or are you just wanting to build another machine because, while it was great while it lasted, it's time to upgrade.
  • Being a complete novice to SLI setups, am I asking for more than I can deal with, or has this become a more-or-less routine task?
  • Is SLI, in general, really only "useful" in the current generation? That is to say, 2x 680s = 1x 690. The cycle continues on forever, but is it just... mind-numbingly painful to see the next generation of cards come out and dwarf your fancy setup?
  • Is SLI more geared towards the ultra high resolutions (2560x1600)? I mean this as it relates to 1920x1080. I assume by SLIing 690s, but only using 1920x1080, that I'm really only future-proofing my system for a couple years whereas if I ran at 2560x1600 I would truly be getting tangible performance gains from an SLI setup

Anyway, sorry for the long post, I just... I've been doing a lot of reading, but haven't been getting any of these questions answered.