Originally Posted by Adversity
What are the disadvantages of SLi?
Besides more heat, more power usage, and some games w/ no support for SLi, I can't find anything.
Bear in mind this is coming from someone who's been running dual-GPU setup (both SLi and xfire) for the past 2.5 years and who is a big fan ... so I'm not a hater, just telling it like it is
At lower FPS levels (around 40 and below), a single card can often provide a more playable experience, as SLi can sometime suffer from microstutter that's noticeable at lower FPS. OTOH with two high-end cards in SLi, lower FPS doesn't happen all that often
Also, depending on your board (whether or not you have space between teh cards) and case, sometimes the top card can run rather hot. Personally I recommend avoiding SLi on board/case combo's where you cannot get at least one open slot (preferably two) between the cards, esp. if quietness is important to you.
It's also true that sometimes SLi involves a hassle when new games come out (or benchies like 3dMark11 which had no SLi support for like 1.5 months after it came out). This is especially likely with game demo's ... it seems nV often lag when it comes to adding SLi support to it's drivers prior to the release date of the actual game (see: Crysis 2 demo for a recent example).
The good news on that front is that the problem can very often be worked around simply by renaming the game's .exe to match that of a game where the driver does have a SLi profile.
All in all I don't consider these major issues, esp. since I purposefully bought a very good SLi board with two full slots between cards and don't mind (in fact I often enjoy) tinkering with .exe names (or SLi profiles in nV Inspector) and such to get SLi working on those rare occasions that I have to deal with that.
But a single GPU is definitely the more consistently 'challenge-free' scenario so if you're easily annoyed by things not immediately working how you want ... I'd avoid SLi.