php password_hash benchmark

php -r "$cost = 3; do { $r = microtime(true); password_hash($r, PASSWORD_DEFAULT, ['cost'=>++$cost]); printf('%-10s %.5F' . PHP_EOL, $cost, $r = microtime(true) - $r); } while ($r < 8);"

4          0.00191
5          0.00257
6          0.00493
7          0.00955
8          0.01842
9          0.03663
10         0.07323
11         0.14599
12         0.29214
13         0.58401
14         1.16794
15         2.33511
16         4.66735
17         9.33500