>you're also measuring the startup cost of PHP itself. yup correct
>A simple microtime(true) benchmark loop as used with my test script should be >fine for ballpark estimates agreed >dwarfing the measurement overhead. wouldn't count out random cpu context switch/background noise completely, see my hyperfine benchmark for cost 13: > Range (min … max): 717.3 ms … 754.5 ms 10 runs - over 10 runs, the fastest was 717ms and the slowest was 754ms, so background noise made at least 37ms difference there.. but yeah anyway, here's from your script: hanshenrik@jonathan-dayton:~$ time php bench.php Cost 8: 2.022854 total (0.020229 per hash) Cost 9: 4.176210 total (0.041762 per hash) Cost 10: 8.121596 total (0.081216 per hash) Cost 11: 16.919405 total (0.169194 per hash) Cost 12: 33.059071 total (0.330591 per hash) Cost 13: 66.761731 total (0.667617 per hash) Cost 14: 140.695820 total (1.406958 per hash) real 4m31.854s user 4m13.115s sys 0m2.168s hanshenrik@jonathan-dayton:~$ cat /proc/cpuinfo | head (...) model name : AMD Opteron(tm) Processor 4122 On Tue, 12 Sept 2023 at 18:01, Tim Düsterhus <t...@bastelstu.be> wrote: > > Hi > > On 9/12/23 17:56, Hans Henrik Bergan wrote: > >> web hosters *love* their ancient hardware > > > > No kidding. dreamhost.com host over 1.5 million websites, presumably most > > are on their "Shared Unlimited" package, which runs on > > AMD Opteron 4122, a high-end server CPU from 2010. > > Some benchmarks there: > > It appears your benchmarks are broken, because you're also measuring the > startup cost of PHP itself. You should see an approximate doubling in > time taken for each increase of the cost, but you have 122ms for 9 and > 166ms for 10. > > A simple microtime(true) benchmark loop as used with my test script > should be fine for ballpark estimates, as password_hash() is pretty > heavy, dwarfing the measurement overhead. > > Best regards > Tim Düsterhus -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: https://www.php.net/unsub.php
