From: walk@mrcnext.cso.uiuc.edu (Todd Walk) Subject: Re: 486SXs as Unix Iron? Date: 17 Nov 1992 20:30:45 GMT
I think that some people here don't really understand the economics
of chip production. Here's a little example (w/ some made up numbers,
since I can't get the actual) using the 486SX and 486DX.
Assume you can get 33 DXs on a wafer.
Now the SX is less than 1/2 the size because of no math coprocessor.
It's smaller yet because it uses a smaller line size, making it about
a third the size of the DX. So right off your yield/wafer has tripled.
This allows you to sell the SX at about 1/2 the cost of the DX
(packaging costs are constant, so you must charge more than 1/3 cost).
Now lets say there are 22 different DX sized areas that have faults
that will ruin the chip that is there. DX production has now dropped
to 11/wafer (33%) and the SX production has dropped to 77/wafer (78%).
Now you have 7 times as many SXs/wafer than DXs, allowing you to
charge something like 1/5 the cost per chip.
The SX is a bargain, the 487DX is a rip-off.
Todd Walk
walk@mrcnext.cso.uiuc.edu