Date: Tue, 17 Apr 2007 11:18:30 -0400 From: Kris Kennaway <kris@obsecurity.org> To: "Gelsema, P (Patrick) - FreeBSD" <freebsd@superhero.nl> Cc: freebsd-current@freebsd.org, freebsd-hardware@freebsd.org Subject: Re: Difference between 6.2 and 7.0 Adaptec 39320D - 7.0 performing less Message-ID: <20070417151829.GA1252@xor.obsecurity.org> In-Reply-To: <49836.195.50.100.20.1176808326.squirrel@www.superhero.nl> References: <200704162247.29909.gelsemap@superhero.nl> <20070416230322.GA69661@xor.obsecurity.org> <49836.195.50.100.20.1176808326.squirrel@www.superhero.nl>
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--NzB8fVQJ5HfG6fxh Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Apr 17, 2007 at 01:12:06PM +0200, Gelsema, P (Patrick) - FreeBSD wr= ote: > On Tue, April 17, 2007 01:03, Kris Kennaway wrote: > > On Mon, Apr 16, 2007 at 10:47:24PM +0200, Gelsema, P (Patrick) wrote: > >> Goodevening lists, > >> > >> I am toying with Freebsd 7 to see if it will and how it runs on my new > >> Asus > >> M2N mainboard. One of the things I noticed is that when running > >> 7.0-Current-200704 the throughput of the SCSI drive seems halved. When > >> running 6.2 throughput is doubled/normal. > >> > >> Throughput is measured with the following command. > >> > >> dd if=3D/dev/zero of=3D/usr/test > >> where /usr resides on da0s1f > >> > >> On 7.0 I get about 33MB/sec > >> On 6.2 I get about 69Mb/sec > >> > >> I did not make any changes, installation is fresh from CD with Minimal > >> as > >> distribution. > > > > Apparently you weren't paying attention during boot, because 7.0 ships > > with heavy debugging options enabled, and tells you about it up front: > > > > "WARNING: WITNESS option enabled, expect reduced performance.\n"; > > > > Recompile your kernel with debugging options disabled before making > > performance comparisons. > > > > Kris > > >=20 > Ok, what you are saying makes sense. I did see the warnings and the bits > in the kernel config. The thing that triggered me was that when paying > attention during boot the SCSI Disk was detected as only 160.00MB/s > instead of the expected 320.00MB/s. The detection of devices is not > subject to debugging, is it? Someone else pointed this out to me, to be honest I didn't get that far in your email after noticing the big blunder of leaving debugging enabled :) I agree that the different speed negotiation is a likely potential cause of poor performance as well, but it really doesn't make sense to be making performance comparisons when one system has all possible debugging enabled and the other has no debugging enabled. Kris --NzB8fVQJ5HfG6fxh Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFGJOVFWry0BWjoQKURAi1tAKDP0Uystg32mQ8dRN1CMuM0ztesXgCg1Ox+ UOmWIfWyrREjKAzzxTSziPY= =WMRF -----END PGP SIGNATURE----- --NzB8fVQJ5HfG6fxh--
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