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From: waters@dover.sps.mot.com (Mike Waters)
Newsgroups: comp.lsi,comp.arch
Subject: Re: predicted yield of BIG microprocessors
Message-ID: <965@dover.sps.mot.com>
Date: 30 Mar 89 05:14:26 GMT
References: <15878@obiwan.mips.COM> <13481@steinmetz.ge.com>
Reply-To: waters@dover.UUCP (Mike Waters)
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In article <13481@steinmetz.ge.com> perley@trub.steinmetz.ge.com (Donald P Perley) writes:
>In article <15878@obiwan.mips.COM> mark@mips.COM (Mark G. Johnson) writes:


>>	What yield is *NOT* good for, is estimating product cost.  It
>>	only measures die cost.  To that you must add test cost(s),

>Many of the additions you list are dependant on the number of dice made,
>but have to be ammortized over the number sold (the good ones), so 
>yield is significant, at least far as fab line and tester ammortization
>is concerned.

The numbers are different again if you look at system costs, e.g. a
Macintosh vs the cost of the microprocessor chip. Case in point, the IBM PC
uses an Intel microprocessor, but Motorola had the highest "value added" in
the original box since the entire power supply used Motorola parts!

The I/O is also Moto, but that too is a small part of the cost. A larger
system like a Sun or Apollo has most (~80%) in just bulk memory. Very low
cost/markup, but still the bulk of the cost.

Add that to system testing, software, and distribution and the actual die
cost gets lost in the noise.