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I suspect that my ATX case's power unit from China provides FAR LESS power than it's supposed to. Is there a way to see (in real time) how much power the whole system is trying to consume and how much is it really getting? Maybe, not in watts, but the voltage is not enough, say, 4.5V instead of 5V. What I really need to know, is should I return the power supply to a shop and buy another one.

Just in case (I don't know, do the following components support power consuming feedback):

  • PCI-E 2.0 PALIT GTX550Ti, NE5X55T0HD09-1061F, 1Гб, GDDR5
  • ECS H67H2-M3 LGA 1155, mATX
  • INTEL Core i5 2300, LGA 1155

NO FORMULAS, PLEASE. I can calculate the summary power on my own. I need REAL TIME consuming data.

NO KILL-A-WATT LIKE DEVICES, PLEASE. I need power consuming data AFTER the power supply, not of the (system + power supply itself).

UPDATE

This is my HW Monitor Screenshot:

enter image description here

UPDATE 2

What I've learned from the answers. This problem is not solvable by people like me. I'm not kinda electrician man, and I have no multimeters/testers. It's too much for me to buy one just for this private task. (Though, I have to, maybe, to be able to solve such tasks in future). Without hardware, I can control voltage only, that can prove the suspicion but not refute. To make the things worse, software like HW Monitor is buggy, since it shows VIN1 values instead of +3.3V like in my case.

P.S. Since I've replaced DDR3 memory, no more BSODs, so I think, the power supply is OK.

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Voltage != (not equal) Power! As @RedGrittyBrick mentions in a comment in one of the answers, without the current, you cannot tell nearly anything about the power consumed. The two things it does tell you is a) how well regulated the PSU output is, and b) whether the voltage may droop as the load increases. –  mctylr Jan 2 '12 at 19:27
    
I should mention Joule's Law namely the form: Power (Watts) = Voltage (Volts) times Current (Amperage), and Ohm's Law. –  mctylr Jan 2 '12 at 19:27
    
So, in other words, you want to measure the efficiency of the power supply? –  sblair Jan 3 '12 at 0:31
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Chances are, if it's a generic PSU in a cheap case, the only thing the PSU will be guaranteed of is being a piece of Junk. for the stability of your system, especially if you plan on overclocking or doing any serious CPU/GPU intensive tasks just dump it and get a decent unit from this list: overclock.net/t/183810/faq-recommended-power-supplies with PSU's you REALLY get what you pay for. with your system, you won't need more than 400W but you definitely want 400 QUALITY watts ;) –  geocoin Jan 3 '12 at 10:09

5 Answers 5

up vote 18 down vote accepted

The information reported by various sensors on modern CPUs, motherboards and graphics cards can be viewed with programs like CPUID's HWMonitor.

enter image description here

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Hm... I see that in 3.3V row I have only 1.89V/1.87V/1.89V values. What does it mean? "A sagging output voltage is a common sign of an underdimensioned power supply" as MSalters wrote, so the system is dying of malnutrition? –  noober Jan 2 '12 at 17:03
    
Please look at my screenshot. I have no 12V row at all and 5V row seems invalid. –  noober Jan 2 '12 at 17:08
    
The 5v does seem off. For the 12v make sure the 4 pin ATX +12 volt power cable is connected to the motherboard. It's the square connector below and to the left of the CPU for your ECS H67H2-M3 motherboard. –  Brian Jan 2 '12 at 18:35

I think you don't quite understand the terms you are using or the physics involved.

"Is there a way to see (in real time) how much power the whole system is trying to consume and how much is it really getting?"

Think of the power supply like a water supply line. Think of the voltage like pressure. If the pressure in the water supply line is correct, then your house is getting precisely as much water as it is trying to consume. If your house tries to draw more water than the supply can provide, the pressure will have to drop.

Maybe, not in watts, but the voltage is not enough, say, 4.5V instead of 5V.

Why is the voltage not enough? The power supply's job is to provide the right voltage, just like the water supply's job is to provide the right pressure.

What I really need to know, is should I return the power supply to a shop and buy another one.

What's the make and model of the power supply? We can tell you whether it's a decent unit or a piece of junk. You can't measure that, just like there's nothing you can measure on a car to tell you if it's well made.

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6  
A sagging output voltage is a common sign of an underdimensioned power supply. –  MSalters Jan 2 '12 at 14:43
    
It's noname unit. –  noober Jan 2 '12 at 16:59
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Now that I think about it, I may have misunderstood what the OP was saying. By "the voltage is not enough", I understood that to mean that measuring the voltage was not enough, he wanted some other source of information. In fact, determining if the voltages are correct is sufficient to tell that the power supply is handling the load. (But it can still be a complete piece of junk that you wouldn't want to keep. I wouldn't judge a power supply by how well it's doing its job, just like I wouldn't buy a car just because a new one drives well.) –  David Schwartz Jan 3 '12 at 2:19

You could presumably work it out with a power supply tester to see if the rails output the voltage they are supposed to.

If you wanted an absolutely accurate realtime way of doing it while the system is running, it would be hugely complicated and involve monitoring each and every power lead's voltage and current, or at the very least, to do so per rail

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"...it would be hugely complicated and involve monitoring each and every power lead's voltage and current..." It's OK, since if only CPU, motherboard and video card are happy with the power level, I'm happy too. I don't need to check HDD or something (I love them less :). Anyway, I have no testing devices. –  noober Jan 2 '12 at 13:35
    
And, I don't need "absolutely accurate" data. If the threshold is over, it's enough for me (it means: yes, your power supply is bad, buy another one). I need real-time to see, how power is changing, when more services/apps are started. –  noober Jan 2 '12 at 13:38
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@noober: If you have no test gear, not even a multimeter, you can't obtain real-time power consumption data for the motherboard, CPU and video card. In a DC system like a PC, power = voltage x current. You have no means of measuring current. –  RedGrittyBrick Jan 2 '12 at 14:14
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@RedGrittyBrick, Thank you for being the first person to mention current, which you need to know (or be able to derive) in order to know the amount of power a computer system is consuming. Voltage alone (i.e. without current) tells you nearly nothing. That said, the on-board power management (APM, ACPI) of present day computers do have some monitoring abilities (A la CPU-Z and lm-sensors) As well as for many GPU cards. –  mctylr Jan 2 '12 at 19:15
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@mctylr: i did mention it in my original answer ;p –  Journeyman Geek Jan 2 '12 at 22:32

What you need is something between your PSU and wall socket.

Try something like this: http://www.velleman.eu/products/view/?id=378012

It will give you the amount of Watts used by your system. You can't have a value of what your system "needs" in terms of power. There are no signals like "I need more power" passed anywhere. You can watch the voltage on different PSU lines to see if there's something wrong going on, but looking at your CPU/Video Card/HDD/Whatever voltages can be misleading due to many technologies of power throttling depending on usage/temperature/other factors.

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Well, according to specs, Maximum Power Draw of GTX550Ti is 116W, some Watts add CPU (95 W), but... Even on max consumption you seems doesn't have the ability to load any up-to-date PSU.

If you really want to get and see real numbers, you can buy, mount and use

with

  • ZALMAN ZM-VPM1 additinal modules-wattmeters (one module per one power line)
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