use Time::HiRes qw[ time ];;

$start = time; 
scoring() for 1 .. 1e6; 
printf "Took: %.15f / iteration\n", ( time() - $start ) / 1e6;;

Took: 0.000000280799866 / iteration

$start = time; 
async{ return 1 }->join for   1.. 10; 
printf "took: %.15f / iteration\n", ( time() - $start ) / 10;;

took: 0.011679911613464 / iteration

print 0.011679911613464 / 0.000000280799866;;
41595.1466781113