[Beowulf] power usage, Intel 5160 vs. AMD 2216

[John Hearns]

Mark Hahn wrote:
>> (you could cobble one together cheaper.. a high quality charger is 
>> probably $50-100, good quality battery is around $20, a high quality 
>> inverter is $200 or so, and then you'd need some sort of transfer switch.
> 
> wouldn't it be nice to find a PSU which could simply take a 12V input?
> battery->inverter->switchingPS->DCelectronics is kind of gross...

Sun (and other manufacturers) of course do 48volt slot-in replacements 
for their AC power supplies, so you can spec a whole rack for telecomms 
use to be 48 volt.
You're right though - a 12volt power supply/smoothing UPS at the bottom 
of a rack with 12 volt feeds would be cool.

Bringing in another strand of this thread, the Intel twins might be a 
great candidate for this - slide out the central PSU and substitute for
a DC one (*)

But as for DIMMS - these have heatsinks on the DIMM.
http://news.com.com/2300-1010_3-6147638-1.html
Look behind the copper CPU heatsinks, the DIMMS are on the right in each 
case.
The PSU is in the centre, and just unlatches to slide out.

We've shipped these twin systems, and they don't seem to run as hot as 
you might fear.




(*) Flight of fancy - if the 12 volt PSU were physically smaller,
could there be room for some active cooling device? Glycol loop up
and down to the systems above and below (with one way valves so you 
could unrack a system!)
The PSU is in the wrong place for heat extraction though - the air very 
firmly runs front to back.