rails w/1.9 slower than w/1.8

rails_bench.sh

# with rails 3.0.3
rails new bench
cd bench/

rvm use --create ree-1.8.7-2010.02@bench
gem install bundler && bundle
time rails runner
# real	0m1.007s
# user	0m0.796s
# sys	0m0.196s

rvm use --create ruby-1.9.2-p0@bench
gem install bundler && bundle
time rails runner
# real	0m2.295s
# user	0m1.808s
# sys	0m0.348s

rvm use --create ruby-1.9.2-p136@bench
gem install bundler && bundle
time rails runner
# real	0m2.661s
# user	0m1.760s
# sys	0m0.332s

rvm use --create ruby-head@bench # head on 2011.01.16
gem install bundler && bundle
time rails runner
# real	0m1.706s
# user	0m1.564s
# sys	0m0.108s

I assume this is on linux?

@rdp, yes it is. Ubuntu 10.10.

I'd really like to see some improvement on this! It's blocking my upgrade to 1.9.