Be scared when someone 'feels' more watts and only wattage
is important. A computer power supply must meet a long list
of essential specs that were even defacto standard 30 years
ago. The question is not about the original supply. The
question is where are all those essential specifications in
this so called 400 watt supply? We cannot scare people enough
when power supplies are sold without claiming to include other
and important specs. Those same specifications may hype a
wattage the supply does not output continuously.
400 watts really does not say what the power supply can
output. If it the instantaneous output power? It is really
the power consumed - which should always significantly larger
than the output power. Some brand name machines rated their
power supplies on constant output power. Therefore a 250 watt
brand name power supply is same as the 400 watt hyped to ill
informed computer assemblers.
Until it specifically claims to meet other essential
requirements, then it probably is one of those so many
inferior supplies dumped into N America that cannot even
output the wattage it claims. Why are so many inferior
supplies dumped? Because so many computer assemblers don't
even know basic electrical principles let alone understand
what those essential requirements are. Instead they buy the
'dumped' power supply only because it is cheaper. A classic
bean counter mentality.
Need more examples? Some supplies even self destructed when
a supply approached (did not obtain) its rated power. What
does one necessary and defacto standard say of power
supplies? All outputs even must be shorted together and still
the power supply is not damaged. Yes, read that again.
Supply must not be damaged even when all outputs are shorted
together. This also demanded by industry standards.
The test only asked a supply to provide its rated wattage -
and still some power supplies failed:
http://www6.tomshardware.com/howto/02q4/021021/powersupplies-15.html
Time and time again, our lab measurements were unable to
verify the output figures represented on the model
identification sticker. And how, exactly, is a computer
purchaser supposed to check the output of a power supply?
Exactly. What really is the output wattage of that supply?
When so many 'dumped' supplies cannot even output their
claimed wattage and when some supplies even self destruct,
then what is its real wattage? The previously posted QTec
example demonstrates a common problem with supplies that do
not provide a long list of specifications. Computer
assemblers are only concerned with the one spec they
understand - dollars - and hype another using mystical
reasoning - wattage.
Be wary of advise that only discusses wattage and that fails
to discuss other, critically important functions. Most every
computer has more then enough power with a 300 watt power
supply. But this means it is really a 300 watt supply. Too
many who recommend supplies do not even know how to measure
that wattage.
