Newsgroups: comp.sys.ibm.pc.hardware
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uupsi!rodan.acs.syr.edu!amichiel
From: amichiel@rodan.acs.syr.edu (Allen J Michielsen)
Subject: Re: 486SX - Intel now telling lies
Message-ID: <1991May23.205937.25386@rodan.acs.syr.edu>
Organization: Syracuse University, Syracuse, NY
References: <1991May14.200856.1431@ux1.cso.uiuc.edu> <1991May15.210339.17118@unlv.edu> <1561@aoa.UUCP>
Distribution: usa
Date: Thu, 23 May 91 20:59:37 GMT

In article <1561@aoa.UUCP> rich@aoa.utc.com (Rich Snow) writes:
>In article <1991May15.210339.17118@unlv.edu> whitney@jimi.cs.unlv.edu
>>If you have been following the threads on the 486sx you have probably
>>heard alot of negative response to Intel's market ploys.
>trade article:
>> ....  In addition, the 20Mhz 486sx chip delivers a 40 percent greater
>>performance than the 33Mhz 386 processor.
>>Does anyone else have an idea as to the
>>performance difference between the 486sx-20 and the 386-33?

>They could be comparing a 486 using the builtin numeric coprocessor
>to a 386 without a numeric coprocessor.

   The NEW 486-sx is a full 486 with the coprocessor EXCLUDED.  Several trade
journals have had detailed technical articles about how much better and faster
the 486 is in a system.  In making the 486, several improvements to the
386 microcode were made (much in the same way that the v20 & 8088 compared)
which speeds up the system.  Then, several components other than the 80386
& 80387 were included in the 486.  This resulted in less cpu handshaking with
peripheral control chips.  Even when the coprocessor is removed (as in the 
486 SX) this reduced handshaking and time decreased op times (effectively)
increase system performance.
   I won't go into the 40% figure (other than I can't) but to say that as
most vendors are doing, they have taken one of a small number of situations
to calculate 'throughput'.  In the real world, you'd NEVER see 40%, but the
difference is there.  I have 25 Mhz 386's, 33 Mhz 386's, & 25 Mhz 486's. 
The 486 is faster in every cpu benchmark than either.  In a real world number
I'd hesitate to say, but would guess at about 10% to %15, maybe as high as
25%.
   I however, give intel great credit for the 486 chip.  This new chip will
provide (soon) cheap 486 products.  It basically will drop the 386 to 286
prices or below, and really squeeze down the market.  However, after you have
a cheap clone 486sx system, you can add a coprocessor at anytime, simply by
replacing the 486sx with a 486-dx (or whatever they call it,..,.).  On the
repair front, it allows me to keep a fairly cheap 486 sx in stock at an 
affordable price for system repair/diagnosis.  If a 486 fries, I can pop in
the 486 sx, and order a replacement, allowing the system to return to
service (basically, with obvious limitations...) immediately.....

al
-- 
Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University
 InterNet: amichiel@rodan.acs.syr.edu  amichiel@sunrise.acs.syr.edu
 Bitnet: AMICHIEL@SUNRISE 
