32 bit vs 64 bit computer ?

[Daniel Kidger]

>I want to know the exact definition of the 32 bit computer (PC ) vs 64 bit
computer.
>I don't know how much(the maximum number) the 32 bit computer vs 64 bit
makes exact calculation without error.
 
It is a common misunderstanding to equate a 32 bit compiter with 32-bit
numbers in calculations. 
For example my old ZX-Spectrum was an 8-bit computer (and so could only
address 64kB of memory) but stored floating point numbers in 40 bits. 
 
What also can add to the confusion is that Intel Pentiums (which are 32-bit
machines) have always had 64-bit floating point numbers, but internal to
the CPU floating point units they are stored as 80-bits. 
 
 
>and With different architecture PCs - for example AMD, Intel, MAC cpu , Is
it possible to communicate the calculation results each other ?
>and With same os - for example LINUX, Is it possible to make one beowulf
Using Alpha(64 bit) & Intel(32 bit) Computers ?
 
Your other question was about communication between heterogeneous
architectures. This again has always been possible. Before MPI
(unfortunately) came to dominate message-passing, PVM was the standard
library used. PVM is designed for heterogeneous systems. For example I have
a code that uses MPI internally on both a Cray T3E and also a Fujitsu
Vector Processor but which uses PVM to communicate between the two big
machines.
 
 
Yours,
Daniel.

--------------------------------------------------------------
Dr. Dan Kidger, Quadrics Ltd.      daniel.kidger at quadrics.com
One Bridewell St., Bristol, BS1 2AA, UK         0117 915 5505
----------------------- www.quadrics.com --------------------


 

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