Date: Mon, 3 Jul 2000 19:38:34 +0200 From: Gerhard Sittig <Gerhard.Sittig@gmx.net> To: freebsd-stable@FreeBSD.ORG Subject: Re: Dump takes ages on SCSI. (several times faster on IDE) Message-ID: <20000703193834.Q5945@speedy.gsinet> In-Reply-To: <200007030344.UAA19117@freeway.dcfinc.com>; from chad@DCFinc.com on Sun, Jul 02, 2000 at 08:44:32PM -0700 References: <14687.42282.873585.2561@trooper.velocet.net> <200007030344.UAA19117@freeway.dcfinc.com>
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On Sun, Jul 02, 2000 at 20:44 -0700, Chad R. Larson wrote:
> As I recall, David Gilbert wrote:
> > I have a PIII/450 with a venerable Adaptec 2940UW and a
> > Quantum 9G SCSI disk.
>
> Oh, man. You're making me feel old. A 2940UW is "venerable"?
> What's that make my 1540C?
I didn't watch the start of the thread, but are _you_ the one
complaining about the duration of SCSI operations? And is this
controller installed in a machine with PCI slots?
If so, I'm very tempted to scream out loud "Aha!". If not, never
mind. :)
The Problem with aha1542 (ISA busmaster capable controller) in
PCI boards is that it is located "at the end" of a long chain to
memory. Chances are, busmastering will not work at all behind
the PCI to ISA bridge since all the PCI devices have higher
priority and the ISA gadget never gets any access granted or at
least always too late. You're better off with a PCI controller.
Another thing bubbles up: When adaptec switched from 1542B to
1542C people moaned about "nothing works any longer". But it
just was that suddenly sloppy (cheap) cable caused problems when
it worked before due to the "better" signal form of the new
electronics (sorry, I lack better words, but the signal was
"sharpened" in the new model which definitely is an improvement).
It's just that now fell back what the user did wrong before.
This is much like hardware failing under UNIX when it has been
working for years under DoS.
virtually yours 82D1 9B9C 01DC 4FB4 D7B4 61BE 3F49 4F77 72DE DA76
Gerhard Sittig true | mail -s "get gpg key" Gerhard.Sittig@gmx.net
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