Path: utzoo!attcan!uunet!crdgw1!crdos1!davidsen
From: davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr)
Newsgroups: comp.arch
Subject: Re: Parity (was: Time between memory failure)
Message-ID: <2102@crdos1.crd.ge.COM>
Date: 7 Feb 90 20:12:07 GMT
References: <1911@sunquest.UUCP> <38420@apple.Apple.COM>
Reply-To: davidsen@crdos1.crd.ge.com (bill davidsen)
Organization: GE Corp R&D Center, Schenectady NY
Lines: 20

In article <38420@apple.Apple.COM> baum@apple.UUCP (Allen Baum) writes:

| Actually, especially when it comes to PCs, parity migh be a loss rather
| than a win, but not for the reasons you'd suspect. Often, it's the parity
| generating circuitry that's the critical path, and it fails more often than
| the memories. Thus, you get lots of parity errors that aren't really errors.
| Its the parity checking and generating circuitry that's the weak point.

  I can't say you're wrong about that because I don't have the detailed
stats on all the computers in the world, but I did ask one of the repair
guys here about memory vs. parity circuit failures, and he said it was
memory virtually all the time. They maintain at least 800 machines which
are PCs or PC clones with parity checking.

  Given a choice I wouldn't buy a computer without parity, because a
wrong answer is a lot worse than no answer at all to me.

-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
            "Stupidity, like virtue, is its own reward" -me