There's a great article on Techreport on the micro-stutter phenomenon. http://techreport.com/articles.x/21516 And describes a metric that could be used to quantify it (99th percentile frame time). We all know FPS hardly captures the whole picture, so seems another metric like this could only help paint a better picture. Interesting tidbit toward the end. Both AMD and Nvidia are working on solving this problem, though apparently Nvidia has a solution in their cards for while called frame metering.