[Beowulf] Re: Purdue Supercomputer

[Karen Shaeffer]

On Sun, May 11, 2008 at 06:47:11PM -0500, Geoff Jacobs wrote:
> Karen Shaeffer wrote:
> <snip>
> > If the motherboard is powered down, then the IPMI board can
> > restart it and can also report failures at the system board level.
> > So the system board power distribution must be distinct from the
> > IPMI power distribution, even when they connect to a node on the
> > system board that has power all the time. Is that reasonable? If
> > so, then it appears to me that a full IPMI implementation on the
> > system board would need that distinct and independent power
> > distribution that used to be on the daughterboard, if that
> > capability is to be maintained. That is all I really meant with my
> > comment.
> You want a persistent, fault tolerant +5V supply. Anyone have any
> thoughts about exactly how stable +5V standby off the PCI rails really is?

Hi Geoff,
Following my line of thought, the issue is only whether the PCI rail(s)
powering all the IPMI circuitry are completely isolated from the
rest of the system board circuitry or not. If true, then it would
be equivalent to a daughterboard implementation. If false, then it
would not.

Thanks for your comments,
Karen
-- 
 Karen Shaeffer
 Neuralscape, Palo Alto, Ca. 94306
 shaeffer at neuralscape.com  http://www.neuralscape.com