Compare: gem executable, bundler binstubs, bundle exec gem executable

0-Ruby-1.9.3-p194

$ time rspec --help > /dev/null                                                                                                                                                                                                               
real    0m0.292s
user    0m0.221s
sys     0m0.064s

$ time ./bin/rspec --help > /dev/null                                                                                                                                                                                                         
real    0m1.167s
user    0m1.017s
sys     0m0.137s

$ time bundle exec rspec --help > /dev/null                                                                                                                                                                                                            
real    0m1.731s
user    0m1.522s
sys     0m0.193s


# Rails gem executable vs script/rails vs binstub rails vs bundle exec rails

$ time rails runner "1 + 1"
real    0m4.864s
user    0m3.729s
sys     0m1.117s

$ time ./script/rails runner "1 + 1"
real    0m4.639s
user    0m3.560s
sys     0m1.069s

$ time ./bin/rails runner "1 + 1"
real    0m5.620s
user    0m4.460s
sys     0m1.136s

$ time bundle exec rails runner "1 + 1"
real    0m6.098s
user    0m4.909s
sys     0m1.159s

1-Ruby-1.9.3-p194-falcon

$ time rspec --help > /dev/null                                                                                                                                                                                                               
real    0m0.244s
user    0m0.168s
sys     0m0.069s

$ time ./bin/rspec --help > /dev/null                                                                                                                                                                                                         
real    0m0.534s
user    0m0.415s
sys     0m0.112s

$ time bundle exec rspec --help > /dev/null                                                                                                                                                                                                            
real    0m0.922s
user    0m0.761s
sys     0m0.150s


# Rails gem executable vs script/rails vs binstub rails vs bundle exec rails

$ time rails runner "1 + 1"
real    0m3.291s
user    0m2.388s
sys     0m0.886s

$ time ./script/rails runner "1 + 1"
real    0m3.228s
user    0m2.325s
sys     0m0.887s

$ time ./bin/rails runner "1 + 1"
real    0m3.735s
user    0m2.788s
sys     0m0.927s

$ time bundle exec rails runner "1 + 1"
real    0m4.063s
user    0m3.099s
sys     0m0.941s

For installing 1.9.3-p194 with "falcon" patches: https://gist.github.com/3126141.