Issue #7968 has been updated by k0kubun (Takashi Kokubun). Just in case, could you measure the time spent on the loop instead of a whole Ruby command? The prelude script sometimes takes a lot of time, the performance varies across different versions, and `time` command would benchmark that as well. You can just call `Time.new` before and after the loop, subtract them, and report the result for each version. ---------------------------------------- Bug #7968: Poor UDPSocket#send performance in ruby 2.0.0 on windows https://bugs.ruby-lang.org/issues/7968#change-105338 * Author: cs96and (Alan Davies) * Status: Assigned * Priority: Normal * Assignee: windows * ruby -v: ruby 2.0.0p0 (2013-02-24) [x64-mingw32] ---------------------------------------- I have noticed that the performance of UDPSocket#send on ruby 2.0.0 on windows is much poorer than that of 1.9.3 or 1.8.7. Running the attahced script on 2.0.0 gives the following... d:\scripts>bash -c "ruby --version" ruby 2.0.0p0 (2013-02-24) [x64-mingw32] d:\scripts>bash -c "time ruby socketsendtest.rb" real 0m2.572s user 0m0.000s sys 0m0.016s However, running the same test with 1.9.3 is much faster... d:\scripts>pik 193 d:\scripts>bash -c "ruby --version" ruby 1.9.3p374 (2013-01-15) [i386-mingw32] d:\scripts>bash -c "time ruby socketsendtest.rb" real 0m0.993s user 0m0.015s sys 0m0.016s Additionally, if I change the send call to a print (commented out in the script), then the performance is fine on 2.0.0.... d:\scripts>pik 200 d:\scripts>bash -c "ruby --version" ruby 2.0.0p0 (2013-02-24) [x64-mingw32] d:\scripts>bash -c "time ruby socketsendtest.rb" real 0m0.907s user 0m0.000s sys 0m0.015s What is send() doing that print() doesn't do that is causing the massive performance drop? Thanks Alan. ---Files-------------------------------- socketsendtest.rb (266 Bytes) -- https://bugs.ruby-lang.org/