From: pjc@YP.melb.bull.com (Paul Carapetis)
Subject: Re: 386/486 questions
Organization: Bull HN Information Systems Australia.
Date: Fri, 22 Jan 1993 05:35:45 GMT

Greetings Wong,

I don't know all of the answers to your questions but have recently been
through the exercise of investigating the various chip types to purchase a
machine for myself.

wongm@latcs1.lat.oz.au (M.C. Wong) writes:

>Hi,
>  I don't play around very much with the PCs, and I would like to know some
>of the followings about 386 and 486 machines :

>1) Are all the main differences of Intel CPU (in the case, 386 vs 486) lie
>   in the architectural improvements as well as speed/performance
>   improvements ? 
>   If so, what margins are each of the different generations have over
>   their predecessor?

I am not sure about the architectural differences but, from memory, the 486
Landmarks about 2 times fater than the same clock speed 386 due to internal
cacheing etc.

>2) I was told that the main difference of 486DX and 486SX are that the
>   former comes with inbuilt on-board 80487 co-processor, is that true ?

True.

>   If not, what are the main differences ?
>   How about between 368DX and 486SX ?

The 486SX is faster and has the 486SX instruction set which is a superset
of the 386DX.

>   Also, what is 486 DLC ?

This is a chip built by TI and may be bought with either a TI or a Cyrix
stamp on the case.  It is designed as an upgrade path for a 386 motherboard
and is 386 pin-compatible.  It does support the full 486SX instruction set
and comes with a separate FPU which gives the chip set the full 486DX
instruction support.  It also has an inbuilt "graphics accelerator" which,
according to the data-sheet, allows it to run Windows faster than a genuine
486DX of the same speed.  Its FPU is its main let down as it only performs
at about 70% of the speed of the DX.  It is, however, a very viable
alternative for someone wishing to upgrade their processor from a 386 to a
486 without changing the motherboard.  I also found that buying a system
with this chip works out to be about $500 cheaper than a 486DX.

Remember that the DX33 can be turned into a 66MHz machine, but what you see
is what you get with the DLC.

>3) What is 486SLX ? By the way, I am most curious about the codes DX, SX,
>   SLX, DLC , what do they stand for ?

I think you mean the SLC??  The SLC is the TI upgrade for a 386 SX to a
486SX.  Where the DX and SX come from, I couldn't tell you, but I can tell
you about the first two letters of the TI acronyms:

S = SX compat   D = DX compat
L = Low power (they have power management built in which makes them perfect
               for laptops and portables)

Maybe the C stands for (C)ompatible???

>  Many thanks in advance, amd I appreciate email answers.

I will post this as well as mail it to you as othe rpeople may be
interested.

Blueskies,
Paul
--
| Paul Carapetis, Software Advisor (Unix, DOS, C)|   Phone: 61 3 2464944     |
| Software Development Services                  |   Fax:   61 3 2464445     |
| Bull HN Information Systems Australia P/L ---------------------------------|
| Internet: pjc@melb.bull.oz.au            | There are only two experiences  |
Newsgroups: aus.computers