threadtest.rb

require 'thread'
t = ARGV[0].to_i
c = ARGV[1].to_i
0.upto(t) do |i|
   thread = []
   0.upto(c) do |j|
     thread[j] = Thread.new { }
   end
   0.upto(c) do |j|
      thread[j].join
   end
end
puts "Done"

# time ruby ./threadtest.rb 400 1000
# 
# Done
#
# real	0m7.370s
# user	0m6.679s
# sys	0m0.687s