[rc5] Re: Supercomputers & Bovine, Q&A

Murray Stokely murray at cdrom.com
Mon Aug 4 22:39:12 EDT 1997


  This sounds like an argument from 20 years ago ;)  RISC vs CISC has
long been settled, the winner?  neither (a hybrid)!  RISC chips often
are much faster simply because the instruction set is smaller, so that
a executing more instructions per second than a CISC chip is
meaningless.  The RC5 math exemplifies that better than anything else.

  I always thought PPC chips were hybid as opposed to true RISC like
SPARCS and Alphas.  Can anyone with more PPC knowledge shed some light
on this for me?

On Mon, 4 Aug 1997, Kevyn Shortell wrote:

% 
% Well see, what your all forgetting, is that the X86's also have hardware
% rotate..... so of course you'd see it outperforming alpha's, which don't
% 
% However, you don't see X86 with hardware rotate, out performing PPC with
% hardware rotate, so saying that, RISC is faster than CISC, is not in itself
% a wrong thing to say.
% 
% In this case, it's quite obvious, that it is =)
% 
% Kevyn
% At 4:29 PM -0700 8/4/97, Murray Stokely wrote:
% >% Naanaanaano, you take the whole thing to easy. You can't just claim that
% >risc
% >% is faster then cisc, you can only say that it is different (if you consider
% >% a problem where the cisc'er can play their card of complex instructions they
% >% are of course in advantage). But speaking about the performance of the 604e:
% >% The PowerPC-architecture includes a hardware rotate-instruction
% >("rlwimi" and
% >% "rlwinm"; the mnemonics sound stupid but these instructions are very
% >powerful!)
% >% and they don't need to "shift left","shift right" and "or" as other risc-
% >% machines.
% >% I think it has been mentioned very often in this mailing list, that x86,
% >Power-
% >% PC and 68K are good architectures for RC5-encryption because they
% >support hard-
% >% ware rotates ...
% >
% >It probably would have been easier to point out that his entire
% >argument that RISC is better was pointless especially in this
% >context.  CISC machines such as x86's are outperforming RISC machines
% >such as alphas that run at over twice the clockspeed.
% >
% >Murray Stokely
% >
% >----
% >To unsubscribe, send email to majordomo at llamas.net with 'unsubscribe rc5'
% >in the body.
% 
% 
% Kevyn Shortell       |
% kevyn at valuserve.com  |  BABYLON 5: Our Last Best Hope For Televised SciFi.
%                      |
%                      |              Sheridan/Zathras in '97
%                                
% 
% 
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% To unsubscribe, send email to majordomo at llamas.net with 'unsubscribe rc5' in the body.
% 


Murray Stokely

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