🚀 go-pugleaf

Jeffery D. Walker (walkej2@eng.auburn.edu) wrote:

: [Defines the bus]

: The MAJOR slowdown for a computer is NOT the cpu speed or the clock 
: speed, but the BUS SPEED!!!  If someone dissagres with me, try taking a 
: few computer engineering/electrical engineering courses and come back and 
: we will talk.

Hmm, a few people reading USENET belive it or not, have taken these
wonderful CE/EE classes, and have various pieces of nicely framed papers on
the wall to prove it.

: this is why a 8088 is NOT considered a 16 bit machine, even though it 
: has 16bit registers.  a 8086 is a 16 bit machine, ONLY because it has a 
: 16 bit bus, no other reason; and it is this reason that makes it that 
: much better.  This is also why a 100MHz-486DX-4 is slower (on average) 
: than even a 75MHz P5. the bus speed/width.(among other things)

This inane arguement as been going on for a while, but for all intents and
purposes, 8088 and 8086 are 16 bit CPUs, and the 386, 486, Pentium
Processor, and "P6" are 32 bit CPUs, this despite the fact that 386sx CPUs
have 16 bit external data bus, and The Pentium Processor has 64 bit
external data bus paths.  now, if you're a motherboard designer, then for
you, looking from the outside in, the 8088 looks like a 8 bit CPu, 8086
looks like 16 bit, and Pentium Processor looks like 64 bit.  It doesn't
change the fact that most reasonable CE/EEs around will take the internal
data bus width as the defining "bitness" of the processor. Just go ask any
one of your CE/EE profs, I'm sure that you'll be told that yes, 8088 really
is a 16 bit CPU.

: -------------------------------------------------
: Jeffery Walker                  Auburn University
: 04 CPE                       Computer Engineering
: walkej2@eng.auburn.edu
: "Real programmers don't document.  If it was hard
: to write, it should be hard to understand."
: -------------------------------------------------

: On 15 Aug 1995, Peter Payne wrote:

: > Dan Pop <Dan.Pop@mail.cern.ch> wrote:
: > 
: > > The size of the data bus is pretty irrelevant to the bitness of a processor.
: > > The sizes of the general purpose registers _and_ the ALU are the important
: > > factors.  This is what makes the 8088 a 16-bit cpu, the 386SX and the
: > > Pentium 32-bit cpu's and the 68000 so difficult to define :-)
: > 
: > What, in physical terms, is a bus and how would a 32-bit bus look
: > differently from a 16-bit one?
: > 
: > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
: > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
: > When I arrived at San Francisco airport, I surprised there are many
: > Americans around here. I thought American people had a large mind, warm
: > heart and were very kind. But American was fatter than Japanese.
: >                                 - Mieko-chan
: > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
: > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
: > 
: >