Fastest way to remove files

Method # Of Files Deletion Time

rsync -a –delete empty/ s1/ 1000000 6m50.638s

find s2/ -type f -delete 1000000 87m38.826s

find s3/ -type f | xargs -L 100 rm 1000000 83m36.851s

find s4/ -type f | xargs -L 100 -P 100 rm 1000000 78m4.658s

rm -rf s5 1000000 80m33.434s