*BSD News Article 74409


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From: "Jordan K. Hubbard" <jkh@FreeBSD.org>
Newsgroups: comp.os.linux.hardware,comp.os.ms-windows.win95.misc,comp.os.os2.setup.misc,comp.unix.bsd.freebsd.misc
Subject: Re: HELP: Can I mix memory speeds
Date: Sun, 21 Jul 1996 16:59:35 -0700
Organization: Walnut Creek CDROM
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Message-ID: <31F2C467.167EB0E7@FreeBSD.org>
References: <31E07EA8.66E140D7@henge.com> <31E6880E.408D@nome.net> <4s7rae$m3a@symiserver2.symantec.com> <stephenkDutwB2.52D@netcom.com>
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To: Stephen Knilans <stephenk@netcom.com>
Xref: euryale.cc.adfa.oz.au comp.os.linux.hardware:45170 comp.os.ms-windows.win95.misc:162092 comp.os.os2.setup.misc:17512 comp.unix.bsd.freebsd.misc:24181

Stephen Knilans wrote:
> This is a REALLY stupid statement!  The chance o a memory error is ALWAYS the
> same, REGARDLESS of the O/S!  Also, a crash in UNIX could be so

I think your own ignorance is showing here, and if nothing else you owe
Joerg an apology for referring to his argument as "stupid" when you, in
fact, are busily making it plain that you haven't got the slightest idea
of what this is all about.

Nobody ever claimed that Parity memory would save the world, simply that
it was a heck of a lot better to KNOW when your memory was going flakey
than not to.  With Partity memory, you can at least catch an NMI upon
detection of the error and your UNIX (or any other) OS can then say
"Hey, the state of my hardware isn't looking so hot anymore - I think
it's time to sync the disks and PANIC!!"  If I'm administering the
system in question, you can bet that I'll then start swapping memory
modules until those panics go away because the people I build systems
for RELY on them to be stable, and undetected memory errors can only
lead to pain and suffering of the most non-traceable kind.  My time is
worth more than that, to say nothing of the time of my customers

> MANY people have had computers WITHOUT parity or tests, and have had NO
> problems.  I had several with BOTH, with NO problems!  NOW, though my

Many people drive without safety belts too and don't necessarily kill
themselves.  What does this prove?  Do you advocate driving without
belts too?  God help us all if you're ever called upon to design an air
traffic control system or a server who's reliability actually counts for
something.

Needless to say, I can only ask the Impressionable Youth on this
newsgroup to ignore Stephan's advice entirely.  While it's certainly
true that your personal box may never suffer from memory problems,
should you ever aspire to creating far more fault-tolerant systems, do
NOT heed his advice!  He hasn't a clue and owes us all an apology for so
rudely rebutting the advice of someone who HAS.  Parity/ECC is not just
a sales trick, nor is it a panacea.  What it is is merely one more
valuable diagnostic aid for those trying to create the most reliable PC
systems it's possible to make with today's technology.
-- 
- Jordan Hubbard
  President, FreeBSD Project