Dual Athlon MP 1U units

Robert G. Brown rgb at phy.duke.edu
Sat Jan 26 16:06:51 PST 2002

On Sat, 26 Jan 2002, Joel Jaeggli wrote:

> evaluate their claims based on the design of the power supply. The crucial 
> thing to bear in mind with smp athlons is can the power-supply provide the 
> current rise need when the cpu's switch from idle to going full-bore.

Or in order to turn on an ATX-style motherboard.  A system can easily
place the greatest demand on a power supply in the first second it
starts up.  If a whole lot of systems are trying to start up at once, it
can also be doing it with a wildly fluctuating power supply as an
inductive surge hits the main line.

Remember also that the wattage of a power supply refers to total power
deliverable on all lines, and it has several lines (to e.g.
peripherals, motherboard, switching).  Peak power deliverable to the
particular lines servicing the motherboard may be less.  AMD requires
"certified" power supplies, suggesting that there are power supplies
that nominally have the rated total power capacity that don't actually
provide enough power, perhaps fast enough, somewhere they think they
need it.

Be cautious.  Prototyping is a good idea.  So is getting a vendor to
accept all the risk if they try to sell you something nominally subspec.
Just remember that you ALWAYS risk at least your time...


Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu

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