large rails app starts up 2.7x faster in 1.9.3dev than 1.9.2p290

I've got a large Rails app we are porting from v2.3.12 to v3.0.10.

The app takes almost 60s to startup in development mode using Ruby 1.9.2-p290 on my 2.66 GHz Intel Core i7 MacBook Pro .

The app starts up about 2.7x faster on Ruby 1.9.3dev and the RSpec model tests run about 50% faster.

Will the 1.9.3 RC release have similar performance to 1.9.3dev?

Ruby 1.9.2-p290

   $ ruby -v; time bin/rails runner ""
   ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]
   real 0m50.333s
   user 0m45.566s
   sys 0m2.961s

   $ bin/rspec spec
   Finished in 502.96 seconds
   1792 examples, 492 failures, 53 pending

Ruby 1.9.3dev

   $ ruby -v; time bin/rails runner ""
   ruby 1.9.3dev (2011-09-07 revision 33211) [x86_64-darwin10.8.0]
   real 0m18.275s
   user 0m15.750s
   sys 0m1.587s

   $ bin/rspec spec/
   Finished in 345.59 seconds
   1792 examples, 492 failures, 53 pending

I've got a large Rails app we are porting from v2.3.12 to v3.0.10.

The app takes almost 60s to startup in development mode using Ruby 1.9.2-p290 on my 2.66 GHz Intel Core i7 MacBook Pro .

The app starts up about 2.7x faster on Ruby 1.9.3dev and the RSpec model tests run about 50% faster.

You should try with 1.9.2-head. I think this will be fixed in the next
1.9.2 patch release.

Will the 1.9.3 RC release have similar performance to 1.9.3dev?

Yes.

Startup times on ruby 1.9.2 head is about twice as fast:

  $ ruby -v; time bin/rails runner ""
  ruby 1.9.2p312 (2011-08-11 revision 32926) [x86_64-darwin10.8.0]

  real 0m25.634s
  user 0m23.242s
  sys 0m2.057s