[Beowulf] Re: Beowulf of bare motherboards

[Andrew Piskorski]

At Mark Hahn's suggestion, I checked the rated amperage on the +3.3
volt line is for each supply.  That didn't seem to correlate with
anything though, so I've recorded all the amps here:

     Rated Amps for each line:
     Volts: +3.3, +5, +12,  -5, -12, +5 Sb
Nodes, PSU  ----  --  ---  ---  ---  -----
2,   TTake:   30, 40,  18, 0.3, 0.8, 2.0
3,     MGE:   20, 45,  24, 0.6, 0.6, 2.0
3, Enermax:   28, 30,  22, 1.0, 1  , 2.2
4, Sparkle:   14, 25,   8, 0.8, 0.8, 0.8

The ratings on the -5 V line seem to line up pretty closely with my
"how many motherboards can this supply power up" metric, but, the 20
pin ATX power connector on the motherboard doesn't even HAVE a -5 V
line, right?  Any thoughts on what the driving factor here could be?

ThermalTake Purepower HPC-420-302 DF, Active PFC, 420 W
+3.3 V:  30 A
  http://www.newegg.com/app/ViewProductDesc.asp?description=17-153-005
  http://www.newegg.com/app/viewProductDesc.asp?description=17-153-005R
  $53 +$7 from newegg.com
2 nodes, 175 W, PF 0.98,  $34.25 per node
3 nodes, would not boot, [$25.67 per node]
4 nodes, would not boot, [$21.38 per node]

MGE SuperCharger, 600W
+3.3 V:  20 A
  http://www.newegg.com/app/viewProductDesc.asp?description=17-167-010
  $48 +$7 from newegg.com
2 nodes, 175 W, PF 0.66,  $31.75 per node
3 nodes, 255 W, PF 0.67,  $24.00 per node
4 nodes, would not boot, [$20.13 per node]

Enermax EG301P-VB, 300 W
+3.3 V:  28 A
  http://www.newegg.com/app/viewProductDesc.asp?description=17-103-423
  $31.50 +$7 from newegg.com
2 nodes, 155 W, PF 0.67,  $23.50 per node
3 nodes, 226 W, PF 0.68,  $18.50 per node
4 nodes, would not boot, [$16.00 per node]

Sparkle FSP250-61GT, 250 W
+3.3 V:  14 A
  Ancient, used to power my old AMD K6-II 380 MHz dektop.
2 nodes, 170 W, PF 0.64
3 nodes, 241 W, PF 0.64
4 nodes, 331 W, PF 0.65

-- 
Andrew Piskorski <atp at piskorski.com>
http://www.piskorski.com/