I understand that having two graphics cards can result in stuttering. Do monster cards such as the new GTX 690, with two GPU's inside them, have the same problem?
Dual GPU cards should be privy to all of the faults of a normal CF/SLI setup; with that being said I've never really noticed the stuttering problems most people claim to have even when running two separate cards.
Anecdotal evidence, but there it is.
I'll chime in since I typically run the nvidia SLI around here.
I used to notice some microstuttering in some games with my dual GTX-460 setup but it was so far and few between that it was a minor issue (except for Borderlands, that kind of got annoying). But it's been quite some time since I've seen any stuttering problems.
The GTX 690 isn't the first time nvidia's done something like this. Look up the GeForce 7950 GX2 and I want to say there was a card in the 8000 series that did the same thing. I knew someone who had the 7950 at the time and there wasn't any real noticeable microstutter.
Depends on game, cards and drivers. Too many variables to give a definitive answer. Having said that there are many accounts of people having issues when running a multi-card GPU setup but it's not something I've encountered myself as most of the builds that I suggest/build for people/customers are single card.
EDIT: Thought I should make it clear, I don't choose a single card setup due to fear of issues. I choose a single card setup because I find it to run cooler and quieter. As long as that single card can run the games that are required at the resolution specified then that should be good enough while still giving the owner a possible cheap upgrade option in the future.
@stenchlord: I am the same way. I stick with 1 card myself too and I run a dual monitor setup with it. I haven't noticed any kind of stuttering to any of game when I did use them. I ran a 9800GTX and 470 GTX on a duely setup with no stuttering issues in games and what not.
Back in the day I ran 2 8500's SLI, but I don't believe I had any stuttering with them in games that I can remember. As you said that there can be to many variables with it and I completely agree with that statement. It think it does really vary from game, driver and cards.