On Thu, 2007-01-18 at 08:17 -0600, Richard Walsh wrote: > 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.
Absolutely, it's one of the more interesting challenges facing large scale cluster development currently. Large scale in this context is >1000 nodes however, I don't think this is the market Microsoft is targeting. I could of course argue that the answer to the skew problem is going to be a algorithmic one which would mean my previous statement holds. Ashley, _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
