Date: Fri, 18 Jun 1999 09:23:37 +0930 From: Greg Lehey <grog@lemis.com> To: mike@hyperreal.org Cc: freebsd-questions@freebsd.org Subject: Re: Optimizing IDE performance revisited Message-ID: <19990618092337.O9893@freebie.lemis.com> In-Reply-To: <19990617234453.6730.qmail@hyperreal.org>; from mike@hyperreal.org on Thu, Jun 17, 1999 at 04:44:53PM -0700 References: <19990618083444.D9893@freebie.lemis.com> <19990617234453.6730.qmail@hyperreal.org>
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On Thursday, 17 June 1999 at 16:44:53 -0700, mike@hyperreal.org wrote: > Greg Lehey wrote: >>>> My controller is capable of PIO mode 3 (11.1 MB/s in theory). No info about DMA >>>> modes. My question is: is this as optimized as it can be, or no? I haven't >>>> really noticed an improvement, is why I ask. >> >> What does your dmesg output say? You should get something like: >> >> wdc0 at 0x1f0-0x1f7 irq 14 flags 0xa0ffa0ff on isa >> wdc0: unit 0 (wd0): <IBM-DADA-26480>, DMA, 32-bit, multi-block-16 >> >> If you get the "DMA" message, then your chipset does support DMA. >> Otherwise it'll fall back to PIO. > > Ahhhh, thanks! > > wdc0 at 0x1f0-0x1f7 irq 14 flags 0xb0ffb0ff on isa > wdc0: CMD640B workaround enabled > wdc0: unit 0 (wd0): <ST31722A>, LBA, multi-block-16 > wd0: 1625MB (3329424 sectors), 825 cyls, 64 heads, 63 S/T, 512 B/S > wdc0: unit 1 (wd1): <ST31720A>, LBA, multi-block-16 > wd1: 1625MB (3329424 sectors), 825 cyls, 64 heads, 63 S/T, 512 B/S > > So, I'd assume this means, no DMA. I'm afraid so. > Now this is odd. The BIOS is set to enable 32-bit transfers. > Wonder why it's not coming up here like it is on yours. It's a feature of the controller chip set. Yours obviously doesn't support DMA. > Thanks for all the info. You're welcome. Greg -- When replying to this message, please copy the original recipients. For more information, see http://www.lemis.com/questions.html See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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