2017-02-16 19:31 GMT+01:00 Jens Alfke <j...@mooseyard.com>: > > > On Feb 15, 2017, at 11:47 AM, Cecil Westerhof <cldwester...@gmail.com> > wrote: > > > > But the difference between sys can be almost a factor twenty. What seems > very big to me. > > Yup. There is a huge speed difference between the kernel going to the > disk/SSD to read from a file, vs. the kernel reading the data out of its > buffer cache. That’s why the kernel has buffer caches :) > > (And those disk reads can be hugely variable. A hard disk can spend 10ms > or more seeking, and any medium has bandwidth limits, so other processes’ > I/O can greatly slow down your own. I’ve seen filesystem slowdowns of 20x > or more shortly after a user logs in when dozens of processes are launching > at once.) >
Well user/sys is mostly around 10, so it does not have a to big influence on the measurements. ;-) -- Cecil Westerhof _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
