<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><BR><DIV><DIV>On Mar 20, 2006, at 12:01 PM, <A href="mailto:beowulf-request@beowulf.org">beowulf-request@beowulf.org</A> wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Lucida Grande" size="4" style="font: 13.0px Lucida Grande">My greatest question, though, revolves around power distribution.<SPAN class="Apple-converted-space"> </SPAN>It seems </FONT><FONT face="Lucida Grande" size="4" style="font: 13.0px Lucida Grande">kinda weak to simply use one PSU per motherboard, especially if I take the </FONT><FONT face="Lucida Grande" size="4" style="font: 13.0px Lucida Grande">time to devise a cabinet in which to operate the goodies.<SPAN class="Apple-converted-space"> </SPAN>Is it possible to </FONT><FONT face="Lucida Grande" size="4" style="font: 13.0px Lucida Grande">run maybe two or three motherboards off a single power supply, given that </FONT><FONT face="Lucida Grande" size="4" style="font: 13.0px Lucida Grande">the amount of known power committed to run a mobo is light, compared to the </FONT><FONT face="Lucida Grande" size="4" style="font: 13.0px Lucida Grande">total workload of the average 350w PSU?</FONT></P></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV>It is not advised to try to "plumb up" several motherboards together for operation from a single power supply. There is no real power saving advantage by doing this and it will only make for an unwieldily mess. 1) You could easily "overload" an ISA power supply by trying to "parallel" the power leads, even if just to two motherboards ... 2) Power consumption is based on the actual load (the motherboard & drives), not power supply rating = a 350w PSU usually does not run at the maximum rating, but at the actual demand of the load (the motherboard & drives).</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Your best bet: keep each motherboard in its own case with its own power supply. If you have a defective or non-operating power supply / motherboard / case, strip the RAM out and add it to other systems and keep the other good parts for spares. (You might also consider using the funds for you "special" cabinet to acquire more RAM.)</DIV><DIV><BR><BLOCKQUOTE type="cite"> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Lucida Grande" size="4" style="font: 13.0px Lucida Grande">This is a power-saving concept... if I could run 16 mobo's on 8 (or even 6) </FONT><FONT face="Lucida Grande" size="4" style="font: 13.0px Lucida Grande">power supplies, it might be more beneficial to my health and well-being when </FONT><FONT face="Lucida Grande" size="4" style="font: 13.0px Lucida Grande">the electric bill comes in.</FONT></P> </BLOCKQUOTE></DIV><BR><DIV> <P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Lucida Grande">... this is NOT! a power saving concept. The total power "consumed" will be done by the total number of system motherboards, plus RAM, plus drives, plus monitor(s) plus added accessories. In fact by "stressing" 8 power supplies to run 16 motherboards (and generating the extra heat), your total electric bill will actually go up, not down.</P><P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Lucida Grande"><BR class="khtml-block-placeholder"></P><P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Lucida Grande">Ed Karns</P><P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Lucida Grande">FireWireStuff.com </P><P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px Lucida Grande">(I have personally built more than 1000 ISA systems, plus quite a few of my own design.)</P><DIV><BR class="khtml-block-placeholder"></DIV> <BR class="Apple-interchange-newline"> </DIV></BODY></HTML>