(In reply to Sinisa Bandin from comment #15) > Without parallel: > real 0m43.247s > user 0m32.279s > sys 0m14.510s > > With parallel: > real 0m6.568s > user 0m30.678s > sys 0m9.899s The fact that parallel execution uses less user and sys CPU made me wonder: Did you flush the caches before each test?