I don't reboot that often, so it took me a while before I could try it, but my home desktop, also with SSD, gives

  user@twen:~/tmp$ time jruby -e '1'

  real	0m0.664s
  user	0m0.390s
  sys	0m0.110s

for a cold boot. Subsequent startups are 350-400ms. Stock JRuby 1.5.6