dkwok writes:
> How do I measure or benchmark power supply?

Well, unfortunately that answer requires a bit of monkey-work.  First
the easy test -- the voltages.  Get a digital volt meter and stick the
probes into a spare power connector.  Then power up the computer and
run some seek intensive operations on each disk.  Check that the 12v
is rock steady and doesn't sag below 10.8v (the 10% cutoff most things
are spec-ed to).  Repeat on each of the other main supplies (3.3v 5v).
The specs for the 5v and 3.3v only have a 5% cut-off.

Then if you feel really gung-ho, you can measure the current.  I don't
have any great advice on how to do this without buying or finding
someone with a clamp-on DC ammeter.  What you would do then is
carefully separate all the +12v wires coming from the power supply and
clamp the ammeter probe around these wires.  Then do the seek test
again and see if the current exceeds what the PS manufacturer says the
supply can put out.  Repeat for the 5v and 3.3v wires.

There are also non-clamp on ammeters which are much cheaper and easier
to find.  Using one of those would require you to cut or unsolder all
the wires that go to one of the rails of your power supply and insert
the ammeter in series with those wires.  Thats quite a bit of work.

-wolfgang
-- 
Wolfgang Rupprecht    <wolfgang@wsrcc.com>     http://www.wsrcc.com/wolfgang/
Coming soon: GPS mapping tools for Open Systems. http://www.gnomad-mapping.com/