Oliver Fromme wrote:
Mark Kirkwood wrote:
> Exactly, that's why I did the comparison - I think you missed the part
> where I mentioned the 2 systems were *identical* with respect to cpus,
> memory, mobo - in fact even the power supplies are identical too!
So I assume your benchmark measured the performance of the
zero and null devices under FreeBSD and Linux.
No - that was peripheral to the benchmark, and I should not have sent
that message 'cause actually I've taken dev/zero and /dev/null *out* of
the picture - check earlier messages with the .c prog attached, I'm
using read(2) and lseek(2) to access a "real" file, that just happens
(i.e. has been arranged) to be cached!
This is a quote from the "cstream" docs: "These special
devices speed varies greatly among operating systems,
redirecting from it isn't appropriate benchmarking and
a waste of resources anyway."
I suggest you try cstream (ports/misc/cstream) instead of
dd. It supports built-in zero creation and data sink, so
you don't have to use the zero and null devices at all,
eliminating their overhead. It would be interesting how
that will change your benchmark numbers.
Thanks - I was suspicious of these special files, but had no evidence!
Cheers
Mark
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