Date: Mon, 11 Jan 1999 08:16:14 -0500 From: Lee Cremeans <lee@st-lcremean.tidalwave.net> To: "Kevin G. Eliuk" <kevin_eliuk@sunshine.net> Cc: current@FreeBSD.ORG Subject: Re: ide_pci.c Message-ID: <19990111081614.A624@tidalwave.net> In-Reply-To: <Pine.BSF.3.96.990110225835.280A-100000@vanessa.eliuk.org>; from Kevin G. Eliuk on Sun, Jan 10, 1999 at 11:49:33PM -0800 References: <19990111002530.A1443@tidalwave.net> <Pine.BSF.3.96.990110225835.280A-100000@vanessa.eliuk.org>
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On Sun, Jan 10, 1999 at 11:49:33PM -0800, Kevin G. Eliuk wrote:
> On Mon, 11 Jan 1999, Lee Cremeans almost wrote:
>
> > dd if=/dev/rwd0 of=/dev/null bs=1024k count=50
> >
> > on a quiet (single-user) system. I haven't done any filesystem-throughput
> > tests yet...this is the raw throughput through the controller.
>
> The patches allowed me to build the kernel, and I don't get the same
> results at boot time. With the final results of your test show similar
> to yours.
>
> Take a note of the "dmesg" output in my case and compare them to the raw
> read/write. I'm not sure what to make of this really, ... other than
> this motherboard and chipset really suk :-(
>
[snip]
> wdc0 at 0x1f0-0x1f7 irq 14 on isa
> wdc0: unit 0 (wd0): <Maxtor 90840D6>, 32-bit, multi-block-16
> wd0: 8010MB (16406208 sectors), 16276 cyls, 16 heads, 63 S/T, 512 B/S
> wdc0: unit 1 (wd1): <Maxtor 71084 AP>, DMA, 32-bit, multi-block-32
^^^^^
This drive sucks almost as much as the board. :/ Maxtor 7000-series drives
are notoriously slow, and the earliest (like the 7060 and 7120, made way
back in 1991-1992) had reliability problems.
Enable DMA on the DiamondMax 8GB, with "flags 0xa0ffa0ff". You'll like what
you see.
> wd0
>
> -------Sequential Output-------- ---Sequential Input-- --Random--
> -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
> Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
> CATHERNA 64 2698 77.0 7241 42.8 2730 19.4 2828 74.7 7980 31.2 95.2 4.4
>
> wd1
> -------Sequential Output-------- ---Sequential Input-- --Random--
> -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
> Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
> CATHERNA 64 3338 96.5 4120 21.8 1678 13.4 3584 95.7 4485 19.2 50.5 2.1
^^^^ ^^^^ ^^^^ ^^^
Here's the biggest thing DMA buys you -- more CPU time. Notice that it takes
more CPU to move single characters than to move huge blocks -- this is
because large chunks of data are what DMA shines at.
--
+--------------------------------------------------------------------+
| Lee Cremeans -- Manassas, VA, USA (WakkyMouse on DALnet and WTnet)|
| lcremean@tidalwave.net| http://st-lcremean.tidalwave.net/~lee |
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