softdep is not the only mount option that can speed up disk access. There is also an option called
noatime.
From
mount(8)
Code:
noatime
Do not update atime on files in the system unless the
mtime or ctime is being changed as well. This option is
useful for laptops and news servers where one does not
want the extra disk activity associated with updating the
atime.
With an SSD disk it probably will not make much difference, but with "spinning rust" disks it makes a difference.