Benchmark: timing 100000 iterations of round1, round2...
    round1: 65 wallclock secs (64.59 usr +  0.00 sys = 64.59 CPU) @ 1548.23/s (n=100000)
    round2: 47 wallclock secs (47.78 usr +  0.00 sys = 47.78 CPU) @ 2092.93/s (n=100000)