Tested on a fairly recent iMac

time ./parallel-exec.sh 8

baseline                       soft card marks
--------                       ---------------
Total realtime: 73677 msec     Total realtime: 72886 msec 
real	1m13.943s              real	1m13.152s          
user	5m35.184s              user	5m35.356s          
sys	1m27.364s              sys	1m23.214s          
