> in the cluster above, I choose a chassis (AIC) which has a large centrifugal
Which? I noticed some of their designs redirect all heat from the powersupply into the side of the rack. > blower, rather than a bunch of 40mm axial/muffin fans. a much larger cluster > I'm working on now (768 nodes) has 14 40mm muffin fans in each node! while > I know I can rely on the vendor (HP) to replace failures promptly and without > complaint, there's an interesting side-effect: power dissipation. of 12 fans > pointing at the CPUs are actually paired inline, and each pair is rated to > dissipate up to 20W. so a node that idles at 210W and 265W under full load Wow, 10 watts per 40mm fan? Really? I've a broshure from Sunon handy: 40x40x28mm 9200rpm 2.6 watts 40x40x28mm 11000rpm 4.0 watts 40x40x28mm 13000rpm 6.8 watts. The 56mm is 15.5 watts, but having 12 fans that large seems bordering on insane.. I'd expect there wouldn't be much room for anything else. That would be a square of fans, er 16cm on a side > can easily consume 340W if the fans are ramped up. ouch! 75 watts difference, hrm, 75/12 = 6.25 watts difference per fan between the low rpm cool state and the hot state... larger than I'd guess. Maybe HP uses substantially more power hungry fans than sunon. -- Bill Broadley Computational Science and Engineering UC Davis _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
