# max_workers => 32
$ time perl rtoa-pgatram-mce.pl t1.txt t1.txt t1.txt t1.txt
rtoa pgatram start
time 0.052 secs

real    0m0.075s
user    0m0.122s
sys     0m0.170s

# max_workers => 64
$ time perl rtoa-pgatram-mce.pl t1.txt t1.txt t1.txt t1.txt
rtoa pgatram start
time 0.070 secs

real    0m0.093s
user    0m0.195s
sys     0m0.441s