Cup processing & unpredictability (was Re: MEDIA: Natasha in Mean Magazine)

From: Emlyn (emlyn@one.net.au)
Date: Wed Apr 04 2001 - 02:21:09 MDT


> April article is now out.
>
> Natasha
>
> http://www.natasha.cc
>
> "I always disagree when people claim that computers are predictable. They
are not. ... The main reason that these process(es) are unpredictable is
because the disk is a shared resource among dozens of simultaneous
processes. The timing of each is dependent on memory fragmentation, disk
fragmentation, cup load and micro variations in cup processor speed. There
are so many variables that it is virtually impossible to duplicate the exact
environment again. Add to that networking or human input, and the system
becomes totally unpredictable."
> Harvey Newstrom
>

I find that memory fragmentation and cup load are quite entangled... memory
fragmentation decreases with cup load, but then a full cup can re-fragment
memory if you are not careful. Cup processor speed tends to increase as the
cup processor (that's me) decreases the cup load, in the hope of decreasing
memory fragmentation. This whole process speeds up if there is excessive
disk fragmentation, because cup processing accelerates whilst running
scandisk. This in turn can lead to excessive cup reloading, and eventual
refragmentation of memory even as cup processor speed increases.

I agree... at such a point, and under the influence of such variables, the
system can become entirely unpredictable.

Emlyn James O'Regan - Managing Director
Wizards of AU
http://www.WizardsOfAU.com
emlyn@WizardsOfAU.com
"Australian IT Wizards - US Technology Leaders
Pure International Teleworking in the Global Economy"



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