Date: Mon, 02 May 2005 16:17:45 -0500 From: Jonathan Noack <noackjr@alumni.rice.edu> To: Steven Hartland <killing@multiplay.co.uk> Cc: freebsd-performance@freebsd.org Subject: Re: Very low disk performance on 5.x Message-ID: <427698F9.8030501@alumni.rice.edu> In-Reply-To: <004101c54f57$abc04220$b3db87d4@multiplay.co.uk> References: <19879.1115061648@critter.freebsd.dk> <004101c54f57$abc04220$b3db87d4@multiplay.co.uk>
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[-- Attachment #1 --] On 5/2/2005 3:43 PM, Steven Hartland wrote: > ----- Original Message ----- From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> >>> To eliminate various parts of the subsystems I've just tested: >>> dd if=/dev/da0 of=/dev/null bs=64k count=100000 >>> Read: 220Mb/s >> >> This is a very interesting number to measure, you'll never >> see anything else going faster than that. Presumably >> this is -current ? > > Nope thats 5.4-STABLE this should be at the very least > 260Mb/s as thats what the controller has been measured on > linux at even through the FS. Um... not quite. That was the number you listed for S/W RAID5. In that case you're not benchmarking the controller in the same way; the controller is just serving requests with no RAID processing overhead at all. Could you get results for Linux that bypassed the filesystem but used H/W RAID5 like you are with FreeBSD? >>> Compared with: >>> dd if=/usr/testfile of=/dev/null bs=64k count=100000 >>> Read: 152Mb/s -- Jonathan Noack | noackjr@alumni.rice.edu | OpenPGP: 0x991D8195 [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (MingW32) iD8DBQFCdpj9UFz01pkdgZURAiy4AJ9gNWWnE/F4Wnui9HVk5c/UDZNYMwCgxQYx H1N2wcElnMeLOMyjAz7YYQs= =sXiJ -----END PGP SIGNATURE-----
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