This example benchmarks the time taken to draw a line consisting of 5000 separate segments into an HTML5 Canvas, using any of the composition modes.
Watch the ‘Time of Last Set’ numbers to see the difference between the various composition modes while the benchmark progresses to plot 5000 line segments.
This benchmark accompanies this Canvas benchmark, which uses the ‘source-over’ default composition mode.
source: gist.github.com/gists/3331545