PC 80486

DULANEY at UCLAUE.MBI.UCLA.EDU DULANEY at UCLAUE.MBI.UCLA.EDU
Mon Jan 25 23:50:00 EST 1993


!!In article <1993Jan25.090410.12066 at gserv1.dl.ac.uk>, 
!!schnorr at tournesol.versailles.inra.fr (Kirk Schnorr) writes:
!!|> I was wondering if anyone out there could inform me about the relative

[ much good discussion deleted  to which John Penniston aptly replied]

!Chip		Internal	External	Floating
!Designation	Data Path	Data Path	Point Unit?
!-----------	---------	---------	-----------
!386DX		32 bits		32 bits		No
!386SX		32 bits		16 bits		No
!
!486DX		32 bits		32 bits		Yes
!486SX		32 bits		32 bits		No
!	As you can see, Intel changed the meaning of "SX" between the 386
!and 486 chips.
                               
I'd just like to add a bit more to the pot.
                                                               Run @ 2X
Chip	     Internal   External   Floating     8K Internal     speed   
Designation  Data Path  Data Path  Point Unit?    Cache       internally?
-----------  ---------  ---------  -----------  -----------   ----------
386SX	     32 bits	16 bits	     No             No            No
386DX	     32 bits	32 bits	     No             No            No

486SX	     32 bits	32 bits	     No             Yes           No
486DX	     32 bits	32 bits      Yes            Yes           No
486DX2	     32 bits    32 bits      Yes            Yes           Yes
                                                 ^^^^^^^^^^^^^^^^^^^^^^^
                                                  additional speed boosts

   Does any of this speak to the point of which processor you should buy?  Not 
really.  Most software (90%) is written to run on 16 bit processors.  I think 
windows 3.1 now incorporates a little 32 bit code but not much.  Some of the 
newest windows programs incorporate 32 bit code but again not much.  NO 
software, to my knowledge, have been written that REQUIRE the 486 chip.  A 386 
machine with a 387 math coprocessor is identically functional (as far as
software is concerned, though you might notice a slight speed difference) to a
486 chip. Furthermore, currently very few programs utilize the math
coprocessor portion of the 486, though this may change rapidly. The primary 
advantage of a 486 over a 386 is SPEED.

  SO... what should you do?  As always, the decision boils down to dollars. 
Buy the most powerfull machine you can comfortably afford.  I'd shy from 386SX
but other than that, 32 bits is 32 bits.  You may opt to buy a (slightly)
cheaper 386 but purchase more RAM so you can multitask in Windows more easily 
or you could add a tape drive to facilitate backups.  Certainly, if you can
afford it, you would want to buy a MEGA PC with 80486, 32 MB RAM, 600 MB hard
drive, tape backup, etc, but, for most, the decision is a big balancing act. 
I hope I haven't complicated things too much. :) Just my 2c.

Tom Dulaney
Graduate Student
Molecular Biology Institute
University of California, Los Angeles




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