Worker-threads to Strategies: Performance Follow-up

When I was last examining the simplification of the mandelbrot-shootout entry I neglected one point: to confirm that the multithreaded performance of the program was maintained after I had made my modifications. First we can see the parallel performance under 4 cores for the original:

Note that this is about a 3.5x speedup.

Now in the simplified version, where the strategies from Data.Parallel.Strategies are used, we see:

Which is slightly slower than the old version (which is consistent with performance under 1 core), with the speedup now in the ballpark of about 3.3x. 

The absolute times are about 50ms vs 53ms, respectively.