Let's look at how Fraps and FCAT data compare in a few more games, while keeping an eye on the multi-GPU systems for evidence of micro-stuttering problems. Then, we'll address micro-stuttering in little more depth.
Borderlands 2 is noteworthy in this context not just because it's a great game, but also because it's based on the incredibly popular Unreal engine, like a whole ton of other titles. Interestingly enough, our results for this game show incredibly close correspondence between Fraps timing and FCAT frame delivery. Yes, that's what you're seeing in the plots above—not just a single distribution, but two that almost entirely overlap. If you look closely, you can see that even the spikes tend to overlap. The peaks are a little higher in Fraps in several cases, but usually not by much. We do see a little "fuzziness" at a few spots in the Radeon HD 7970 CrossFire plot from FCAT, which likely indicates some micro-stuttering, but it's relatively minimal.
Every one of our metrics confirms that Fraps and FCAT are virtually in unison here. That's a good thing, because it should mean that the content of frames being displayed will match the timing of their appearance onscreen quite closely. It also gives us quite a bit of confidence that we're measuring the "true" performance of these graphics solutions in Borderlands 2 between these two tools.