Chris Dagdigian <[EMAIL PROTECTED]> wrote: > Subject: Re: [Beowulf] The Walmart Compute Node?
> It is dangerous to project *your* particular use cases and workflows > upon the community at large. > > Most of the clusters I end up building or working on (academic, > government and corporate sites) are intended to support periodic > spikes in computing demands. Exactly. It's not just academic. This mode of parallel operation comes up any time the user needs the result to proceed with a project, and either their time has value or time is critical. So cutting a job down from 2 hours to 6 minutes even occasionally can be justified economically even if the cluster sits idle the rest of the time. BUT, while it is sitting idle you'd naturally like it to burn as little power as possible. The one thing that the C7 processors offer that the main line AMD and Intel processors don't, at least last time I looked, was the ability to run really, really, really slowly, and so drop standby power on the processor to something negligible. Clearly it would be better if the AMD and Intel processors kept their capabilities and added equivalent low power modes. Vincent Diepeveen <[EMAIL PROTECTED]> wrote: > Would it be interesting to open a discussion how to reduce sound of > cheapo clusters as well? Been there - this is a VERY hard nut to crack. The problem isn't "cheapo", the problem is peak power and getting rid of it. Sound insulation is very closely related to heat insulation. The net result is that it's relatively easy to cool a cluster, or to muffle its sound, but fiendishly difficult to do both at the same time. The cheapest way to "quiet" a cluster is to move it to a place far away from the people who would be disturbed by its noise. In our case, that was a separate machine room (which already had a chilled water line for cooling). Knowing what I do know, if I absolutely had to put a cluster in a location close to users (as in, inside an office space) I'd build a big sound insulated box with a large AC coiling coil inside it and big (large diameter) fans to drive the air around in a defined path. Then run the freon lines out to a condenser outside the building. Notice that this is still, essentially, moving the cooling away from the users. It's relatively easy to contain sound inside a box if the only holes in it are the small ones for the power cable,the AC coolant, and a drip line for the coil condensation. Note that this is essentially the approach Sun took with it's cluster in a shipping container products, although I believe those are water cooled. Run a building air cooling duct into a box containing the cluster and you'll have lots of fun keeping the noise out of the building's ventilation system and from spreading to nearby offices. Regards, David Mathog [EMAIL PROTECTED] Manager, Sequence Analysis Facility, Biology Division, Caltech _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
