[RC5] Performance on P-IV

Ryan Malayter rmalayter at bai.org
Thu May 10 10:53:36 EDT 2001

A P4 is slower, clock-for-clock, that both the Pentium III and Athalon.
However, the P4 was designed with deeper instruction pipelines, so that it
could be run at a higher clock speed than Athalon or P3 on the same type of
This is a design/marketing decision made by Intel, as a higher clock speed
makes for better marketing to lay people who don't know jack about
That said, a P4 can be very fast when code is optimized for it. And RC5
cracking is a very specialized use of a processor - it is in no way
indicative of the processor's general performance potential. All of the
cores in the current "official" dnet client are specifically hand-assembled
for the P3 or Athalon architectures. Similarly hand-optimized P4 cores might
make it a faster dnet machine than anything else out there.

-----Original Message-----
From: Ferry van Steen [mailto:td at salesint.com]
Sent: Thursday, May 10, 2001 4:31 AM
To: rc5 at lists.distributed.net
Subject: [RC5] Performance on P-IV

Hey I've got some sad sad sad statistics. I hope there is an explanation for
this because else I have to advise everybody NOT to buy Pentium-IV's because
this is sad.....
Ok.. the distributed net does NOT recognize P-IV's yet so it does a micro
bench and selects Core #2 RG Class 6 which is the same core running on
P-II's. Knowing this you would suspect a performance increase on a P-IV 1400
compared to P-II 400 of 1400/400 = 3.5 which would mean 350% performance
increase in MHz so the pure calculative power should increase 350% also...
My P-II 400 on Core #2 RG Class 6 Win2K with some services runs 1,128,585,13
according to dnetc -benchmark rc5
The P-IV 1400 (1.4GHz) running -benchmark rc5 Core #2 RG  Class 6 only makes
a LOUSY 1,824,190,86 on a freshly installed WinME without any services.
This is only a lousy 161.64% (182419086/112858513*100) increase over a 350%
increase of MHz's
To give another example
(This runs on linux btw, and the tests I've done the rc5 clients run faster
on linux in any case (using the exact same hardware RC5 goes faster under
linux than under win)
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 is scary shit... Hehe Guess I
shouldn't buy intel... Atleast not until everything is optimized because
this is really sad.
Hope somebody can explain this....

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