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Actual power consumption

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April 17, 2010 12:25:22 PM

i am buying the Coolermaster's Real Power Pro 1000W and wanted to know that whatever be the actual power consumption inside the PC, does every power supply consumes exactly its max rated power from the mains or only whats attached to it ?



a c 243 ) Power supply
April 17, 2010 12:54:03 PM

The power supply will draw only what it needs to convert to DC for your components.
In order to provide the full 1000 watts the draw at the wall would be 1250 watts with an 80% efficient psu.
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a c 91 ) Power supply
April 17, 2010 2:07:37 PM

I agree with Delluser1, and would like to add that you can conserve power consumption by the "Power Options" settings in Windows 7.

1000 Watts will serve almost every possible application that you can install in a PC, including SLI/Crossfire. However, do not overload the electrical outlets by having other power intensive devices in the room.

Check your circuit breaker that supplies the room in which your computer is situated. Most bedrooms (except the master bedroom) in US homes have 15 Amps service circuit breakers. Sometimes, this 15 A is shared by 2 adjacent bedrooms. If this is the case, please make sure that you do not overload the outlets in the room housing your computer.

You can make a rough calculation of the Amps required by lights, by allowing 1 Amp per 100 Watts of lighting. However, for computers, you must take into account the efficiency of 80%, therefore every 100W of computer power consumed will draw 100/0.8 = 125 W from your room outlet; about 1.14 Amps (per 100W).

Other devices such as TVs, have the power rating clearly marked on the label.
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a b ) Power supply
April 17, 2010 2:15:01 PM

yes, even thoug hu have a 1000w psu, it wont always use 1000watts. if u are simply checkin ur email and ur internal components only need 200watts, then the psu may pull 240watts if its 80% eficient...
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April 18, 2010 6:57:26 AM

shovenose said:
yes, even thoug hu have a 1000w psu, it wont always use 1000watts. if u are simply checkin ur email and ur internal components only need 200watts, then the psu may pull 240watts if its 80% eficient...


so that means that if the internal PC power usage is only 240 watts , then from the electrical mains too the power drawn will only be around 240 watts , and no more

is that correct?





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April 18, 2010 8:37:26 AM

Are all the images necessary?

No, the combined power consumption of the components is less than the amount drawn at the wall because as already said no power supply is 100% efficient. The conversion from AC to DC causes some wastage. Efficiency depends not only on the PSU model but also the load it is under. A PSU that is rated for 750W but is only supplying 200W to the system is often horribly inefficient. Therefore to make sure you minimise your power bill you should purchase a PSU that fits the system it's going to be used in, with some leeway for capacitor aging (which reduces maximum output over time) and potential system upgrades.
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April 18, 2010 9:44:08 AM

i saw in wikipedia the actual tdp in watts for most gpus.
they are ranged to maximum of 320watts(hd 5970 eyefinity and peak of 294 for normal hd 5970).

so my question is why would someone need power supply of 800w and above.
i think we need to consider that if only we do crossfirex or sli.
right?

Can someone say what power supply would be best for a quad or hexa core processor
with 290watts tdp graphics card?
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April 18, 2010 1:17:24 PM

randomizer said:
Are all the images necessary?

No, the combined power consumption of the components is less than the amount drawn at the wall because as already said no power supply is 100% efficient. The conversion from AC to DC causes some wastage. Efficiency depends not only on the PSU model but also the load it is under. A PSU that is rated for 750W but is only supplying 200W to the system is often horribly inefficient. Therefore to make sure you minimise your power bill you should purchase a PSU that fits the system it's going to be used in, with some leeway for capacitor aging (which reduces maximum output over time) and potential system upgrades.


ALL THE IMAGES I HAVE ATTACHED HAVE NOT HELPED EVEN AN IOTA TO ENABLE YOU TO ANSWER MY QUESTION CORRECTLY !!!

would you please reread my post

i am not asking about the max output of the power supply at 80% efficiency !!!

i am not asking about PSU output at whatever the efficiency is !!!

i am asking about actual power consumption inside the PC and it's relation to the actual wattage drawn from the mains !!!
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April 18, 2010 1:32:45 PM

capital_one said:
i am asking about actual power consumption inside the PC and it's relation to the actual wattage drawn from the mains !!!

Which is precisely what I have already answered. You asked:

"so that means that if the internal PC power usage is only 240 watts , then from the electrical mains too the power drawn will only be around 240 watts , and no more is that correct? "

And I said:

"No, the combined power consumption of the components is less than the amount drawn at the wall..."

I'm not sure how I can answer your question any differently.
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April 18, 2010 1:39:50 PM

Hmm, lets see. My rig consumes (at the wall) around 275watts and 1 amp idle.
Under load (gaming) it pulls around 475 to 500 watts and up to 6 amps.

It is a Q66@3.6 dual 4890,s in CF both overclocked and 2 water cooling
loops with 7 fans 2 pumps and 2 hhd,s.
This is with an efficient Seasonic X750 PSU.
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April 18, 2010 1:43:55 PM

randomizer said:
Which is precisely what I have already answered. You asked:

"so that means that if the internal PC power usage is only 240 watts , then from the electrical mains too the power drawn will only be around 240 watts , and no more is that correct? "

And I said:

"No, the combined power consumption of the components is less than the amount drawn at the wall..."

I'm not sure how I can answer your question any differently.



THATS WHY I ATTACHED THE IMAGES !!

i am asking again as per what you are stating


if the combined power consumption of the components is 240 watts how much more will be the power drawn from the wall ?

please answer with reference to this figure of 240 only

please answer in terms of this number only

that means your answer should be greater than 240

please give me a figure which you mean to imply
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April 18, 2010 1:45:41 PM

capital_one said:
THATS WHY I ATTACHED THE IMAGES !!

i am asking again as per what you are stating


if the combined power consumption of the components is 240 watts how much more will be the power drawn from the wall ?

please answer with reference to this figure of 240 only

please answer in terms of this number only

that means your answer should be greater than 240

please give me a figure which you mean to imply



To be EXACT, it depends on the efficiency of the PSU.
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April 18, 2010 1:50:25 PM

Without knowing the efficiency of your PSU when the system is drawing 240W I can't possibly give you a number. But to know the efficiency you would need to measure the power draw at the wall anyway.
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April 18, 2010 2:38:36 PM

randomizer said:
Without knowing the efficiency of your PSU .



see the very first post

will you see that please
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a b ) Power supply
April 18, 2010 3:01:49 PM

its a cm realpower 1000w, random

this off the cooler master website:
Specifications
Model RS-A00-EMBA

Type ATX Form Factor 12V V2.3 / SSI standard EPS 12V V2.92

Dimension (W / H / D) Standard ATX 150 x 86 x 180mm

Input Voltage 90~264V (Auto Range)

Input Current 15A@ 115 Vac / 8A@ 230 Vac

Input Frequency Range 47~63 Hz

PFC Active PFC(0.99)

Power Good Signal 100~500 ms

Hold Up Time >17 ms

Efficiency 83%(200W) / 85%(500W) / 81%(1000W)

MTBF >100,000 hrs

Protection OVP / OCP / OTP / OLP / Short / Full Protection

Output Capacity 1000 Watts Continuous

Max. Output Capacity 1,200 Watts

Operation Temperature 0~50°C Nominal Input Voltage?

Safety CE / cUL / TUV / NEMKO / BSMI / FCC / CCC / C-tick / GOST

Fan Ultra-silent 135mm fan with intelligent speed control

Certifications nVIDIA SLI / 80 Plus

Connector M/B 24 Pin Connector x 1
CPU 4 Pin x 1
CPU 8 Pin x 1
PCI-E 8 Pin x 2
PCI-E 6 Pin x 4
4 Pin Peripheral x 6
SATA x 8
4 Pin Floppy x 2


http://www.coolermaster.com/product.php?product_id=2519

so basically the psu is 83% efficent at 200watts, so figure that out your self!
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a c 91 ) Power supply
April 18, 2010 3:27:58 PM

capital_one said:
THATS WHY I ATTACHED THE IMAGES !!

i am asking again as per what you are stating


if the combined power consumption of the components is 240 watts how much more will be the power drawn from the wall ?



If your computer uses 240 Watts of power, then the power drawn from the outlet will be 240/0.8 = 300 Watts assuming an 80% efficient power supply. In this case, 60 Watts will be converted to wasted heat.

Divide the actual power consumed by the computer by 0.8 (80%) and you will get the amount of power drawn from the outlet.
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April 19, 2010 3:16:35 AM

Specifications mean nothing. The PSU is not always running at 80% efficiency, it varies with the load (as I said in my first post). That is why I can't give an accurate number.
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a b ) Power supply
April 19, 2010 3:28:40 AM

look up a few posts, at what i copied from the website. it says, 83% at 200w
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April 19, 2010 6:35:22 AM

I think looking on JohnnyGuru's site for a review that contains the efficiency across the entire load range would be better than assuming that the manufacturer is being truthful ;) 
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April 19, 2010 8:02:20 AM

shovenose said:


so basically the psu is 83% efficient at 200watts, so figure that out your self!


exactly that's what i wanted to know

i don't think any cooler master PSU will run below 70% efficiency, whatever the load be

and i am obviously not going to launch rockets with my PC,

therefore a 70 % efficiency is acceptable,

isn't it






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a c 91 ) Power supply
April 19, 2010 1:38:22 PM

capital_one, you are correct - the 80% efficiency factor will decrease as the PSU temps (and load) increase. However, these are not things to worry about. Just pick a good, high quality PSU, and make sure that it is rated somewhat above the max load that you are going to have on your computer. Take into account the 80% efficiency when you calculate the load. Then add about 25% as a factor of safety.
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April 29, 2010 7:11:21 AM

randomizer said:
Specifications mean nothing. The PSU is not always running at 80% efficiency, it varies with the load (as I said in my first post). That is why I can't give an accurate number.


its really strange for you to ask about the load again and again !!!

don't you know how to read the load in watts which i have already mentioned?

now that's shocking to know !!!

that you do not consider the wattage of 240 to be a LOAD !!!
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April 29, 2010 9:28:21 AM

You're just not getting it. I don't care what the load is, I need to know what the efficiency is at 240W else I can't tell you how much power is being drawn from the wall socket. But to know the efficiency you already need to measure the power draw at the wall, in which case there is no point asking about it in the first place.
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April 29, 2010 9:44:15 AM

randomizer said:
You're just not getting it. I don't care what the load is, I need to know what the efficiency is at 240W else I can't tell you how much power is being drawn from the wall socket. But to know the efficiency you already need to measure the power draw at the wall, in which case there is no point asking about it in the first place.



OH MY GOD WHAT KIND OF A PERSON ARE YOU !!!
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