Ashley Pittman wrote:
On Wed, 2007-01-17 at 08:50 +0100, Mikael Fredriksson wrote
Yes, it is. And more so if this cluster/LAN can also utilize som type
of "MOSIX" system. This will substatially increase the throughput of
"standard serial" processes.
I find this statement hard to comprehend, how can any OS substantially
improve throughput of jobs unless what it replaces is incredibly
deficient in some way? The limiting factor on clusters is the speed of
the hardware, even if some OS magically manages to be say 50% more
efficient doing it's bit than another OS it's still only a tiny percent
of time used, substantial improvements in job throughput can only come
about from better parallel algorithms, better code or faster hardware.
While I agree with this argument, especially at small scale, at
very large scale operating
system derived load imbalance (so-called skew, due to the random
nature of system
call driven interrupts) can destroy scalability, and thus
efficiency. This is worth mentioning,
although I would not expect Windows to improve on Linux in this
context. You need
a light-weight kernel like Catamount to reduce skew.
There is a very good paper showing the effects of skew at scale by
Kerberyson, et al from
Sandia.
rbw
--
Richard B. Walsh
"The world is given to me only once, not one existing and one
perceived. The subject and object are but one."
Erwin Schroedinger
Project Manager
Network Computing Services, Inc.
Army High Performance Computing Research Center (AHPCRC)
[EMAIL PROTECTED] | 612.337.3467
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