[Beowulf] Re: Purdue Supercomputer

[Karen Shaeffer]

On Sun, May 11, 2008 at 04:45:46PM -0400, Joe Landman wrote:
> Karen Shaeffer wrote:
> 
> >Hi Joel,
> >Yes, but a separate and distinct power distribution for that +5 volt
> >supply will then need to be implemented on the system board to support
> >a full IPMI implementation residing on the system board. That was my
> >point. You are confusing power source with implemented PCB power
> >distribution.
> 
> Hi Karen
> 
>   I haven't seen IPMI cards that get their power from any other place 
> than the motherboard slot.  There may be some that have a separate 
> supply, but I haven't run across them.  That is, as long as the power 
> supply is "on", the main system power does not need to be, and the IPMI 
> is powered over a similar bus to that which powers the motherboard 
> network cards.
> 
>   I don't think Joel was confused on this.

Hi Joe,
OK. Maybe no one is confused, I am just not communicating
effectively. Let me try again.

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.

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