[RC5] Performance on P-IV

AMackenzie at edgewater.com AMackenzie at edgewater.com
Thu May 10 15:58:45 EDT 2001


:  Hmmmm my 450 MHz G4 runs just a whisker over 4,000,000 
:  keys/sec per CPU. (I 
:  have a dual processor, so run just under 8 MegaKeys/sec when 
:  I'm not doing 
:  much else.
:  
:  That's 8,889 keys per MHz.
Yet note the slower clock speed, and in general the slower clock speed for
ALL PowerPC's vs. x86.

Top of the line G4 is around 6/700MHz (I can't remember)?  Athlon is at
1.3GHz?


:  From the original message
:  
:  >My AMD Athlon 1000 (1 GHz) scores a friggin' absolutely 
:  awesome 3,538,971.00
:  >Hahaha a 1GHz Athlon is almost TWICE as fast as a stinking 
:  P-IV 1400 which
:  >has 400MHz more under ít's belt. 
:  
:  This means the Athlon under Linux runs 3,539 keys/MHz.
:  
:  which is what the site http://www1.distributed.net/~fordbr 
:  says, showing that 
:  the Athlon is by far the most efficient of the x86 type 
:  chips, but still not 
:  even managing half of what the G4 PowerPC chip can do with 
:  optimised code.

But find a commercially available 1GHz G4.
:-)

Remember, instructions per clock isn't everything!  PowerPC's (and 'RISC'
machines in gerneral) 'tend' to have shorter pipelines, and more latency per
instruction, and thus slower clock speeds. 

If you can do 'foo' in 1 clock, and I do it in 2 clocks, but run at twice
the speed as your clock, then what does it matter?  The output is the same.



"If brute force doesn't work, you're not using enough brute force!"
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