Maybe the result would vary with JRuby or Rubinius (I'd be interested in benchmarks) because not only is Ruby itself not the fastest language, but its main implementation (MRI) is also not the best for speed.
[master] clifff@fair_and_square: ruby -v
jruby 1.7.3 (1.9.3p385) 2013-02-21 dac429b on Java HotSpot(TM) 64-Bit Server VM 1.6.0_43-b01-447-11M4203 [darwin-x86_64]
[master] clifff@fair_and_square: time ruby fair_and_square.rb C-large-1.in.bak
real 6m39.105s
user 6m37.762s
sys 0m19.009s real 2m35.450s
user 2m35.257s
sys 0m0.139s
time ruby -Xcompile.invokedynamic=true file2.rb C-large-1.in
real 1m17.711s
user 1m15.618s
sys 0m0.830s
real 1m37.856s
user 1m39.260s
sys 0m0.854s