To be fair Rick, these stutters cannot be solely blamed on CloD’s coding – have a look at
this article (thanks Flyby) to better understand the mechanics of dual-gpu rendering. If you think about it from a non-technical aspect, the process of alternate frame rendering is prone to this sort of thing purely due to the fact that it takes longer for gpu #2 to render a frame then gpu #1, since the frame has to be sent back to gpu #1 before being sent to the screen. Dual-gpu single cards should be less prone to this, but even in this case there is still some lag as only one of the gpu’s has the task of rendering.
I haven’t had the stutters since one of the early updates, even on my previous 1GB 5850, but found that I could reintroduce them by turning the graphic detail up beyond what the card could reasonably handle. CloD may also not be the best candidate for Sli at the moment either, being that it hasn’t been optimised for it, but even when it is it may not be completely stutter-free. You may find some improvement by lowering the detail, which could improve frame rates to a point that the stutters are no longer that noticeable. As they say, your mileage may vary ...
Probably not what you want to hear, but I would only recommend dual gpu’s over a single faster one in special circumstances – for eg. when using a high resolution on multiple monitors, and then only if they’re in a machine fast enough to feed them data at the required rate. I know graphics card manufacturers will spin all sorts of yarns about increased performance with multiple cards, but you have to realise that their sole motivation for doing so is additional sales
Edit: assuming that the stutters are being caused by the different rendering speed of the alternate frames, you may try increasing the detail settings to reduce the frame rate to a point that the difference has less of a visual impact – i.e. obtaining a smooth frame rate of 30fps instead of a stuttering one at 40fps. Might be worth a try?