$ cat script/test.rb
require File.expand_path('../../config/environment.rb', __FILE__)
5000.times{ print 'a' }

$ RAILS_ENV=production strace -e trace=write ruby script/test.rb > /dev/null
write(1, "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"..., 4096) = 4096
write(1, "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"..., 904) = 904