Date: Thu, 08 Mar 2007 11:39:26 +0100 From: Ivan Voras <ivoras@fer.hr> To: freebsd-stable@freebsd.org Cc: freebsd-geom@freebsd.org Subject: Re: Some Unix benchmarks for those who are interesed Message-ID: <esop53$8ek$1@sea.gmane.org> In-Reply-To: <45EF9B8F.4000201@fluffles.net> References: <20070306020826.GA18228@nowhere> <45ECF00D.3070101@samsco.org><20070306050312.GA2437@nowhere><008101c75fcc$210c74a0$0c00a8c0@Artem> <esk9vq$uhh$1@sea.gmane.org><001a01c7601d$5d635ee0$0c00a8c0@Artem> <eskka8$adn$1@sea.gmane.org><001801c7603a$5339e020$0c00a8c0@Artem> <eskpd1$sm4$1@sea.gmane.org> <20070307105144.1d4a382f@daydream.goid.lan><002801c760e2$5cb5eb50$0c00a8c0@Artem> <esmvnp$khs$1@sea.gmane.org><005b01c760e6$9a798bf0$0c00a8c0@Artem> <esn2s6$1i9$1@sea.gmane.org> <001601c760ee$f76fa300$0c00a8c0@Artem> <45EF2252.1000202@fluffles.net> <45EF253B.8030909@fer.hr> <45EF9B8F.4000201@fluffles.net>
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This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig2251A9A09E3C144AAB0CBD78 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Fluffles wrote: > Ivan Voras wrote: >> Fluffles wrote: >> >> =20 >>> If you use dd on the raw device (meaning no UFS/VFS) there is no >>> read-ahead. This means that the following DD-command will give lower = STR >>> read than the second: >>> >>> no read-ahead: >>> dd if=3D/dev/mirror/data of=3D/dev/null bs=3D1m count=3D1000 >>> read-ahead and multiple I/O queue depth: >>> dd if=3D/mounted/mirror/volume of=3D/dev/null bs=3D1m count=3D1000 >>> =20 >> I'd agree in theory, but bonnie++ gives WORSE results than raw device:= >> =20 >=20 > On what hardware is this? Using any form of geom software RAID? Xeon 5110, 1.6 GHz, see benchmark results on stable mailing list (It's a pretty fast dual-core CPU, core2-based). It's using geom_mirror and the results are with "split" read algorithm. > The low Per Char results would lead me to believe it's a very slow CPU;= > maybe VIA C3 or some old pentium? Modern systems should get 100MB/s+ in= > per-char bonnie benchmark, even a Sempron 2600+ 1.6GHz 128KB cache whic= h > costs about $39. Then it might be logical DD gets higher results since Maybe on Linux, definitely not on FreeBSD. I've never seen per-char bonnie++ results on FreeBSD that give more than 1 MB/s. And before anyone starts debugging my setup, I'm not the only one with such results :) I recall there were reports before which show geom_mirror doesn't achieve better performance with split reads. --------------enig2251A9A09E3C144AAB0CBD78 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) Comment: Using GnuPG with Thunderbird/FreeBSD - http://enigmail.mozdev.org iD8DBQFF7+fkldnAQVacBcgRAox7AKCQZfktHhPE9lcJzzfNYCov6pbhwQCfftX6 kB8u/WW0v2XfvtK8LuI08F8= =diaD -----END PGP SIGNATURE----- --------------enig2251A9A09E3C144AAB0CBD78--
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