I would very much like it if you could post frame latency data concerning SLI 660s with progressively higher AA levels. The only website that seems to have decent info on this is Tom's, and it's only outmoded FPS metrics which would tend to hide memory bandwidth issues as it did with Radeon cards. Even then, it seems pretty clear there are issues.
I can definitely see a case being made for SLI helping alleviate this issue, but that also does open up its own can of worms in terms of usability. There's a lot of games out that don't have great SLI profiles, or need all sorts of workarounds. It's a great option for tinkers and enthusiasts, but it's not a great option for someone who might be new to this sort of thing or just wants a plug and play experience.
As far as coolers go, Kepler just sips power. The old standard advice of going with reference blower coolers for 2-way SLI doesn't hold as much water as it did with Fermi. You're essentially looking at needing to expel ~250-300W of heat, which is pretty in line with a single 570/580. No one would have told you to get a reference version of either of those. I think the reference coolers only begin to shine when you are talking about SLI in mATX or 3-way SLI in ATX. Even if the non-reference coolers start to lose some of their edge, it's hard to still make up for the fact that reference coolers create double the noise that the non-reference coolers make. On top of that, you want to try and stay below that magic 70C level before they begin to downclock.
Sleeve them? (and put the pic in a quote plz
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