Power Supply question - More watts consumes more electricity?

[jiro]

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Hi,

I have a question regarding powersupply, usually i see watts as a way to measure how heavy it eats electricity. you know - like "plantsa - kusug mukaun ug kuryente because 1000watts"

does it hold true to PSU of computers?

i mean, im seeing more and more higher watts PSU - 750, 1000, 1500 even 2000watts.

the power supply itself is consumming power right?
so does it mean more watts consumes more electricity?

say for example, i have
(all psu not connected to anything except just to the power outlet)
300 watts psu
450 watts psu
500 watts psu
750 watts psu
1000 watts psu

- do they all consume the the same electricity or not?

im hesitating to buy a 700 watts psu because i see it as "more watts means high electricity bill".


fellow istoryans - please enlighten me.

[EarlZ]

Your PSU will only draw power relative to the system load, if you have a 1200Watts PSU and your peak system load is 300watts then it wont draw more than that, but having a higher wattage and good brand of PSU saves you a lot of electricity in the long run.. better conversion to 12v/5v/3.3v and lesser power loss.

[dmelsie]

mao gyud tag as og effeciency ang mga branded psu so gamay lang ma waste nga power so eventually maka save ka in the long run

[nirdle_phogi]

Your PSU will only draw power relative to the system load, if you have a 1200Watts PSU and your peak system load is 300watts then it wont draw more than that, but having a higher wattage and good brand of PSU saves you a lot of electricity in the long run.. better conversion to 12v/5v/3.3v and lesser power loss.

well explained..

[poldopunk]

i don't agree completely. efficiency is quite low if the power draw is less than the rated wattage. for 500W PSU, you need to be drawing around 350~400W to get 80~85% efficiency. efficiency goes down when the power draw is too little or too much -- de-rating curve.

[bootbox]

earlz and poldo are both correct
power draw depends on the components sa imo pc
use this to calculate the "power draw" sa imo pc Thermaltake Power Supply Calculator
PSU's have different characteristics
pero "most" is at their peak efficiency at 50 - 80% sa ila rated capacity
then again google is your friend
look for reviews before you decide....

[reishoto]

calculate your power needs, iyang peak gyud, inlcuding your fans and possible upgrades. and buy a psu with only 15 to 20% above your peak. im using a 550w, yet im on crossfire w/ 4830 (in reality, would only need around 400 with my system fans). as what poldopunk had said, naay curve nga peak effeciency for psu (branded ones, ok?).

[poldopunk]

^ @ TS: this is "the" tip that you're looking for. i'm just too lazy to expand my idea earlier.

[jez++]

Parehas ra na sa rice sa kaldero. Kung dako kag kaon, mgkinahanglan kag dako nga kaldero para daghan rice masulod to masatisfy ang imo kagutum. Kung gamay kag kaon then gamay ra pud imo lung-agon.

Kaldero - Power Rating of ur PSU

Rice - Power

Ikaw - Pc and all peripherals connected to it.

Sakto ba ang analogy? hehe!

[jiro]

so it's a myth - 500watts psu consumes 500watts of electricity.

salamats! well explained.