Date: Fri, 17 Dec 1999 11:40:02 -0800 From: Kent Stewart <kstewart@3-cities.com> To: Dale Hagglund <rdh@best.com> Cc: freebsd-questions@freebsd.org Subject: Re: when is it safe to use the 0xa0ffa0ff disk flags? Message-ID: <385A9192.840FCB72@3-cities.com> References: <Pine.BSF.4.21.9912161648580.1526-100000@dogma.freebsd-uk.eu.org> <01ae01bf47e7$08293900$d2630a0a@megared.net.mx> <867lidxtoh.fsf_-_@ponoka.battleriver.com>
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Dale Hagglund wrote: > > "Alejandro Ramirez" <ales@megared.net.mx> writes: > > > Are you refering to the "0xa0ffa0ff" flags???, this flags are for > > improve performance by enabling DMA use, enable the multi-sector I/O > > and the 32BIT I/O modes to IDE Disks. > > How does one know if it's safe to apply those those particular flags > to one's system? If they'll speed up disk activity, I'm all in favour > of them, but I don't want to trash my disks by mistake. > > I'm using 3.2-RELEASE with a kernel built to support ipfw and the bpf > stuff. My disks are Quantum Fireballs, a ST2.1A and KA9.1 > respectively. It isn't a function of the disk as much as an interaction between the disk and the rest of the hardware. It is something you can test before you fix it in the kernel. These parameters can be configured during boot. Changing them at boot time lets you test the configuration and then make it permanent by adding the flags in your kernel. I went from 2-3MB/s to 12-14MB/s. This isn't a trivial improvement :). Kent > > Dale. > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message -- Kent Stewart Richland, WA mailto:kstewart@3-cities.com http://www.3-cities.com/~kstewart/index.html FreeBSD News http://daily.daemonnews.org/ SETI(Search for Extraterrestrial Intelligence) @ HOME http://setiathome.ssl.berkeley.edu/ Hunting Archibald Stewart, b 1802 in Ballymena, Antrim Co., NIR http://www.3-cities.com/~kstewart/genealogy/archibald_stewart.html To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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