sharing a power supply

Alvin Oga alvin at
Thu Jul 3 19:08:05 EDT 2003

hi ya

On Thu, 3 Jul 2003, Alan Ward wrote:

> I am counting on the following maximum draws for
> each motherboard (Duron at 1300 + 512 MB RAM):
> 	15A / 5V
> 	<1A / 3.3V
> 	5A / 12V
> This is _just_ inside the 450W supply's specs -
> I hope they were not overly optimistic.

if you're connecting 3 systems .. that's 45A 
that the power supply has to deliver ...
	-- double that for current spikes and 
	optimal/normal performance and reliability
	of the power supply
if the ps can't deliver that current, than you're
degrading your powersupply and motherboard down 
to irreparable damage over time 

450W power supply doesnt mean anything ...
its the total amps per each delivered voltages
that yoou should be looking at  and how well you
want it regulated ...  there's not much room
for noise on the +3.3v power lines and it uses
lots of current on some of the memory sticks

if the idea of hooking up 4 systems to one ps was
to reduce heat and increase reliability, i think
using multiple systems on a ps designed for one
fully loaded mb/system will give you the opposite
reliability effect

i think 2 minimal-systems per powersupply is the max
for any power supply .. most ps and cases is designed for 
fully loaded case

fun stuff ... lots of smoke tests ... 
( bad idea to let the blue smoke out...
( for some reason, the systmes always stop working
( after you let out the blue smoke
( and blue smoke smells funny too

have fun

Beowulf mailing list, Beowulf at
To change your subscription (digest mode or unsubscribe) visit

More information about the Beowulf mailing list