```
[] ~/projects/jruby $ GEM_PATH=lib/ruby/gems/ GEM_HOME=lib/ruby/gems/ time jruby -S gem list > /dev/null
        2.57 real         9.07 user         0.38 sys

[] ~/projects/jruby $ GEM_PATH=lib/ruby/gems/ GEM_HOME=lib/ruby/gems/ time jruby -S gem list > /dev/null
        2.51 real         8.89 user         0.38 sys

[] ~/projects/jruby $ rvm use system
Now using system ruby.

[] ~/projects/jruby $ GEM_PATH=lib/ruby/gems/ GEM_HOME=lib/ruby/gems/ time jruby -S gem list > /dev/null
        2.50 real         8.52 user         0.38 sys

[] ~/projects/jruby $ GEM_PATH=lib/ruby/gems/ GEM_HOME=lib/ruby/gems/ time jruby -S gem list > /dev/null
        2.55 real         8.53 user         0.38 sys
```