Cached file read performance with 6.2-PRERELEASE

Oliver Fromme olli at
Thu Dec 21 06:08:50 PST 2006

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.

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.

Best regards

Oliver Fromme,  secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
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