Here we take a look at both average (black) and 99th Percentile (coloured) response times of the graphics cards. It is highly unlikely a user will notice any micro stutter (also incorrectly referred to as lag but the effect can be interpreted to be similar) at anything below 30ms but every gamers perception differs.
The graphs above may appear very daunting however, what you want to see is a smooth line (not fuzzy) with very few peaks and troughs. While you are unlikely to notice peaks and troughs below 30ms, any peak above 30ms may be seen as a stutter during gameplay. This will however depend greatly on your own perceptions. Multi card setups are more likely to show frame lag due to the nature of cross communicating to render frames.