This gist compares the performance of Julia, Nim, C++ and R - the latter using either POMP, or LibBi in a simple simulation of an SIR epidemiological model. In addition to keeping track of susceptibles, infecteds and recovereds, I also store the cumulative number of infections. Time moves in discrete steps, and the algorithm avoids language-specific syntax features to make the comparison as fair as possible, including using the same algorithm for generating binomial random numbers and the same random number generator; the exception are the R versions, POMP uses the standard R Mersenne Twister for the random number generator; I'm not sure what LibBi uses. The algorithm for generating random binomial numbers is only really suitable for small np.
Benchmarks were run on a Mac Pro (Late 2013), with 3 Ghz 8-core Intel Xeon E3, 64GB 1866 Mhz RAM, running OSX v 10.11.3 (El Capitan