Re: Do we (nearly) all use totally oversized power supply units ?

Jason Stacy (jjstacy@xxxxxxxxx) writes:
Recently I bought a power device for measuring the real power needed by a computer.
I put this measuring device just between the computers power cable and the power plugin in the wall.

After some days of measuring I was really surprised.

My computer (AMD Athlon XP 64 + PCIexpress) need on average 82 Watt!
Maximum during these days was 112 Watt.

So why do I need a 350 power supply unit in my computer?
Moreover 350W - 400W seems to be the standard.

When one take into account that the power supply unit operates most efficently only
when its is near to full capacity then it seems to me that all these 350W power supply units
are completely oversized.

150W would be sufficient.

All these gamers which run a high level video/graphic cards could buy a 400W PSU.

But for the "normal" office user this is bull ***.

Am I right ? Or what is the reason for these high capacity PSU ?

Jason

It likely costs as much to make a lower current power supply as the higher
current ones. There is a certain amount of overhead that is needed in
terms of parts whether no matter what the wattage, and the cost of the
parts will be a small increment to provide that higher wattage.

On the other hand, you aren't drawing more current just because the power
supply can supply it. So it's not as if having a higher wattage supply
is an ongoing cost.

It's always easier to have backup than failure. Start with a higher
wattage supply, and you won't have to fuss if you start adding a lot
of boards, but if you start adding boards you may have to worry if
you started out with a lower wattage supply.

Michael


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