Date: Fri, 1 Aug 2003 01:26:58 -0700 From: John-Mark Gurney <gurney_j@efn.org> To: Ruben de Groot <bulk@ei.bzerk.org>, mh <mh@nerim.net>, freebsd-hackers@freebsd.org Subject: Re: Ultra ATA card doesn't seem to provide Ultra speeds. Message-ID: <20030801082658.GQ10708@funkthat.com> In-Reply-To: <20030801081503.GA66987@ei.bzerk.org> References: <200307311219.h6VCJLVG053962@spider.deepcore.dk> <3F29D164.6090904@nerim.net> <20030801081503.GA66987@ei.bzerk.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Ruben de Groot wrote this message on Fri, Aug 01, 2003 at 10:15 +0200:
> On Fri, Aug 01, 2003 at 04:33:08AM +0200, mh typed:
> The following comparison is probably bogus, but can anybody explain the
> huge difference?
It's called micro optimization. Linux feels the need to special case
/dev/zero to /dev/null, and instead of even reading/writing the data,
It just ignores the user request, (or does something like set the pages
in the user space to be zero'd.
Also, dual procs won't help your performance when you run a single
process like this. So your are still comparing a 1ghz P3 to a
2.6ghz p4 which isn't even being close to fare. I have a P4 that out
runs my 386, why? :)
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030801082658.GQ10708>