Looks llike a good way to test.
well, the result tells one thing. Crossfire is broken til they fix it.
it is a fact for now, that crossfire 'doesn't help' animation, in fact, makes it a little worse by inserting grunts in the animation sequence. My lab mates have talked about this since a long time ago, and it is one of the reason why my machine is a GTX680 3xSLI + 7970 and not the other way around.
I was able to observe the stuttering myself, and was able to see a clear difference in graphics properties. the stutter cannot be 'observed' so to say, but it results in the overall animation being a lot more 'fake'. Not sure how to say it, but when you have 2 machines side by side, one is crossfire, one is in SLI, and I was asked 'which feels better?', I was able to call it out 100% of the time.
I have 6 associates in the lab, and of the 7 of us, 2 see no difference, so I must say this is a very personal 'perception' thing.
for AMD cards, for now, 1 GPU is about all you need, whatever FPS you get extra with it with crossfire, actually harms animation. (great for benching though! just not for the eye)
Here's a video explaining.. I found this recently.