What's interesting is how much power the fan consumes.. Sunon SG4028 is a 40x40mm fan 28 mm long (single fan). The 16.8 CFM flavor spins at 13krpm and consumes 2.6 watts.
The PF4056 which is a stack of two fans 40x0mm, at 15-18krpm consumes almost 11W to push 27 CFM ( at zero back pressure..) Against 2 inches backpressure, that fan can only push about 17 CFM You could wind up in a situation where the heating from the fan is more than whatever it's cooling. Jim Lux -----Original Message----- From: beowulf-boun...@beowulf.org [mailto:beowulf-boun...@beowulf.org] On Behalf Of Mark Hahn Sent: Friday, January 18, 2013 12:00 PM To: Beowulf Mailing List Subject: Re: [Beowulf] AMD Roadrunner open compute motherboard > As in contradiction to what Mark Hahn says - it needs active cooling. if anyone cares: a dimm dissipates roughly 2W, depending on generation, whether it's LV, number of devices, etc. one of those duplex 14krpm fans is typically rated at about 12W. in a mainstream server, each CPU will dissipate around 100W. typical SATA disks, about 5W. since servers normally have "platinum" plus80 ratings these days, the PSU would need to dissipate ~30W. NICs are normally <= 8W. so even a 1W device needs some airflow, but it's mostly CPUs that count. _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
