[Gllug] IA32? IA64? x86...

[Allen Baranov]

Hi Jon et al,

> CISC - Complex Instruction Set Chip - means that the chip instructions can
> have varying lengths and take varying arguments. All Intel IA32  chips and
> various clones, AMD Athlon.
> RISC - Reduced Instruction Set Chip - instructions and data are all the
> same lengths, which makes pipelining and chip design (theoretically)
> faster, simpler, more efficient, etc. PowerPC, Alpha, IBM Power4, MIPS,
> etc. EPIC - As far as I can tell, mostly marketing bollocks to hide the
> fact that it's really CISC. Itanium.

I was under the impression (when RISC and CISC were being talked about a 
lot....when Motorolla was about to make *the next generation* chips 
(PowerPCs) and kill off intel for good) in simple terms that CISC chips had 
more availible instructions (like sin,cos,etc) but the time spent looking for 
the one you wanted was longer per instruction because of the fact there were 
more of them. I image a "for" type loop with a whole bunch of subroutines. 
Meanwhile RISC has less instructions that are more generic. So they can do 
whatever CISC can do but it may take a few loops because different 
instructions are used. However, the "for loop" would take less time because 
there are less "subroutines" or instructions to go through. So, for complex 
things CISC *may* be faster if it has the dedicated instruction availible, 
whereas RISC will generally go faster. 

This is my simple understandung..can someone more versed in this tell me if I 
have hit-the-nail-on-the-head or missed-the-point-completely or am somewhere 
in between.

Allen Baranov 

-- 
Gllug mailing list  -  Gllug at linux.co.uk
http://list.ftech.net/mailman/listinfo/gllug