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Date:      Thu, 17 Jun 1999 16:44:53 -0700 (PDT)
From:      mike@hyperreal.org
To:        grog@lemis.com (Greg Lehey)
Cc:        freebsd-questions@freebsd.org
Subject:   Re: Optimizing IDE performance revisited
Message-ID:  <19990617234453.6730.qmail@hyperreal.org>
In-Reply-To: <19990618083444.D9893@freebie.lemis.com> from Greg Lehey at "Jun 18, 1999 08:34:45 am"

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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.

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.

Thanks for all the info.


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