Re: Mips vs specint95 for Hall D CDR and white paper

[Franz Klein <fklein@jlab.org>]

Hi folks,

I wouldn't take CLAS reconstruction as a comparison.
We have full (online) analysis programs running at 10 msec/event
and 25 msec/event (depending whether the code is based on the "official"
recsis "shell" and whether lots of histogramming is involved).

For Hall-D the level 3 reconstruction won't take longer than 1-2
msec/event/cpu (cpu: PIII 750, even better with alphas).

Have a nice weekend

Franz


On Fri, 7 Jul 2000, Elliott Wolin wrote:

> Hi Dave,
> 
> Ian tells me that the 750 MHz PIII's give 35 specint95.  Mark and Stepan tell me
> it takes about 100 msec to fully reconstruct CLAS events on a 300 MHz farm node
> (12 specint95, according to Ian).
> 
> Thus CLAS full reconstruction takes 1.2 specint95-sec;  divide by 10 for Hall D
> online filtering, then x2 for safety (includes i/o overhead) (as in chapter 7),
> gives about 0.25 specint95-sec to filter.  (do we still want to use the factor
> of 10 for filtering?).
> 
> If we assume a factor of 10 improvement over 750 MHz for Hall D then a single
> processor will deliver 350 specint95, or a single processor can filter 1400 Hz
> of events.  Duals will process 2800 events/sec. 
> 
> Thus the 180 kHz event rate means we'll need about 64 dual processors for the
> level 3 farm.  Alternatively 180 kHz x 0.25 specint95-sec means we'll need 45000
> specint95 equivalents.
> 
> Chapter 7 needs to be reworded in these terms...I'll rewrite that section if you
> want.
> 
> 				Sincerely,
> 					Elliott
>  
> 
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===============================================================
Franz J. Klein, Thomas Jefferson National Accelerator Facility,
12000 Jefferson Avenue MS 12H, Newport News, VA 23606
Email: fklein@jlab.org, Tel: (757)269-7251, Fax: (757)269-5800
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