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From: stevew@wyse.wyse.com (Steve Wilson x2580 dept303)
Newsgroups: comp.arch
Subject: Re: ECC (was: Re: 1st 64 Megabit DRAM)
Message-ID: <2749@wyse.wyse.com>
Date: 15 Jun 90 20:13:16 GMT
References: <1990Jun14.220128.7904@craycos.com>
Sender: news@wyse.wyse.com
Reply-To: stevew@wyse.UUCP (Steve Wilson x2580 dept303)
Organization: Wyse Technology
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In article <1990Jun14.220128.7904@craycos.com> rh@craycos.com (Robert Herndon) writes:
>ECC is generally only for people who worry about large words
>(or perhaps cache lines), say, 64 bits or larger.  

I haven't found this to be the case. I've seen machines that 
used ECC for 8 bit words(i.e. an ECC memory card for the IBM
P.C.) and LOTS of commercial machines that use ECC on 32 bit
memory organizations.  You'll typically see ECC on mini/super-micros 
built for commercial use. 

> stuff deleted....

>  Even so, what percentage of machines "out there" really use
>SECDED codes?  What percentage of memory chip production do
>these products consume?
>
>Robert Herndon				Cray Computer Corp.

Back in the bad old days, say circa 1978-1979 when the 64k
memory chips were just coming out there was a story running
around Burroughs that Burroughs alone consumed 10% of the 
world's memory production at that time.  All of their machines
at that time had ECC.  Maybe that gives a ballpark answer to
your question.

Steve Wilson