PSU Consumption

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Kills On Site
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PSU Consumption

Post by Kills On Site »

I was wondering, do PSUs of different wattages consume different amounts of power? Would a 400W PSU use more power then a 300W PSU? Assuming they were used in identical systems.
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AmIdYfReAk
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Post by AmIdYfReAk »

yes, obviously..

Voltige X Amps = Watts

so, 300watt PSU = 120V @ 2.5AMPS
400watt PSU = 120V @ 3.333AMPS

and that is Per cycle..
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Survivor
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Post by Survivor »

He means does the actual usage mean anything like 300 watt psu with the pc requiring 250 using less power than the 400 wat psu with pc still requiring 250.

Edit: or you are saying that only the psu determines power consumption
AmIdYfReAk
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Post by AmIdYfReAk »

Well, Sorry, i was a little vague.. the power supply's do use more power when they are highervoltige ( maintain, that we are talking about Say 2 identical branded yet diffrent wattage PSU's ) But its not as much as i am saying,

the powersupply will Hold a residual Charge Determined by the system load.

most psu's will run idle at about 80% load reguardless of the system load on hand, but when puch comes to shove, they will operate at ~110% before blowing.

and somthing else to remember, Psu's are getting more and more efficent, meaning they require Much less Amp's to get the work done.

thus: if you are kickin with a 300watt PSU from say 4 years back.. and you are looking at say, a 400watt PSU right now, you would/should be getting the same power consumption on the unit's reguardless of there diffrent wattige rating.

anyway, this is all from my experance.. I'm no electricion. :)
bork[e]
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Post by bork[e] »

I don't think there are such things as electricions, could be wrong. :p
AmIdYfReAk
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Post by AmIdYfReAk »

Electricians, Pardon me.. >:E
Magestic
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Post by Magestic »

The thing is, it all comes down to efficiency. If a computer uses an actual 230 watt, a good PSU will consume 285 Watt, or a bout 80% efficiency.
So it doesn't matter what the PSU is rated, just (if it can supply enough, that is) how efficient it is. You can have a 550Watt PSU powering that 230 Watt and still consuming only 270Watt or a 300W PSU powering the same system and consuming 310 Watt. (By consuming I mean drawing from the actual electricity from the socket in wall).

ATX2.01 standards require a 70% efficiency though. PSUs will vary a lot though. I seen tests where a Antec Phantom 500Watt PSU will only consume 261 Watt to power a 230watt load, while several Aopen and Nexus PSUs will consume more that 315 Watt.

You can see for yourself, buy a normal cheap power consumage monitor, should be available at any decent hardware store.
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