Kent Sibilev wrote: > Consider this 'tuning': [snip] > > class Test > def run > d=0 > 1000000000.downto(1) { > d = d + 1 > } [snip] > double d = 0; > > for (int i = 0; i < 1000000000; i++) { > d = d + i; > } To be fair, the type of the variable in the Mono example is "double", but the Ruby example uses an int. A more appropriate Ruby version: def run d = 0.0 1000000000.downto(1) { d = d + 1.0 } return d end Alexander.