[Beowulf] AMD64 results...

[Robert G. Brown]

On Thu, 16 Dec 2004, Kozin, I (Igor) wrote:

> Hi Bill, very interesting results.
>  
> > Ah, got icc-8.1 to cooperate, dual 2.2 Ghz opteron+pc3200+2.4 kernel,
> > 915.5MB array:
> > -O1
> > Function      Rate (MB/s)   Avg time     Min time     Max time
> > Copy:        2285.8039       0.2640       0.2800       0.3200
> > Scale:       2206.9798       0.2690       0.2900       0.3000
> > Add:         2341.5554       0.3740       0.4100       0.4200
> > Triad:       2181.9031       0.4060       0.4400       0.4800
> > 
> > -O2
> > Function      Rate (MB/s)   Avg time     Min time     Max time
> > Copy:        2370.4856       0.2570       0.2700       0.3400
> > Scale:       2285.8280       0.2670       0.2800       0.3400
> > Add:         2461.6513       0.3710       0.3900       0.4600
> > Triad:       2285.8229       0.3920       0.4200       0.5000
> 
> pls note that your "average time" is sometimes less than "min time".

In the words of James Bond, "Well, that's a neat trick...";-)

The min/max times are also a bit odd in that they are all two digit
numbers, and the average is a three digit number (%6.4f format).
Something is Not Right.

Good eye, Igor.

   rgb

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu