• ## power consumption

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#2529812

What is the typical desktop power consumption, booted up vs when asleep?  Wattage?  Amperage?

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• #2529815

There is no “typical”. That’s like asking, “What is the typical fuel consumption of cars with 4 wheels?

There are just too many different types and configurations to even define the typical desktop.

I might suggest you visit a good power supply calculator like the eXtreme OuterVision PSU Calculator and plug in some specific hardware components. This will help tell you the maximum power (in watts) that computer will draw.

That said, it is extremely rare for every component (RAM, motherboard, CPU, GPU, drives, fans, etc.) to demand maximum power at the exact same point in time.

Sleep consumption would require you to visit each component’s data sheet and research how much it consumes with in sleep mode – “IF” that spec is even published. I will say in most cases, the newer (in terms of state of the art) the device, the more efficient it will be. DDR5 RAM, for example is more efficient than DDR4.

If you know the wattage, you can calculate current. The basic formula is P=IE (power = current x voltage). Therefore, I = P/E.

Bill (AFE7Ret)
Freedom isn't free!

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• #2529817

If you know the wattage, you can calculate current. The basic formula is P=IE (power = current x voltage). Therefore, I = P/E.

Yes, familiar with this basic formula.  If I can find wattage or amperage I can determine kilowatt hours, or consumption.

• #2529832

If I can find wattage or amperage I can determine kilowatt hours, or consumption.

Not really. The problem is, computer power consumption is never consistent. It is constantly varying from idle, demanding a few watts, up to heavily tasked demanding several hundred watts, then back down again, all in a matter of a few seconds.

I agree with Cybertooth’s suggestions but none of those “log” or keep track of the demands over time. And unless you connect everything (monitors, external drives, etc.) through the UPS or the Kill-A-Watt meter too, you only get a partial picture.

Bill (AFE7Ret)
Freedom isn't free!

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• #2529830

What is the typical desktop power consumption, booted up vs when asleep?  Wattage?  Amperage?

There are at least three ways you can get this info for your machine:

1. You can buy a Kill-A-Watt meter to plug in-between the PC and the electrical outlet, then monitor the wattage in the computer’s various states and while it’s performing specified actions. Very handy little device.
2. If your PC is connected to a UPS, some UPS software will also give you a running total of the power consumption.
3. Finally, the program CPUID HWMonitor will report current power usage for the CPU and the graphics card if you have one.

Doubtless there are other ways to find out, but these are the ones that come readily to mind. Good luck!

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• #2529848

Not looking for precision here- just a sense of what the pc adds to the electric bill- on average!  Could do it with my multimeter, too much rigamarole.

Just got to thinking about this because our electric bill has gone ‘way up due to a sizeable rate increase.

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• #2529831

An old desktop computer I had, Pentium 4, used 225 watts when on.  In hibernate not sleep, it used 0.  LED monitors use 15 to 25 watts.  For comparison my Core i5 laptop uses about 25 watts when on.  A device called a P3 Kill-A-Watt meter costs about \$30 and can be plugged into a computer to give an instant power reading or can measure usage over a whole day or more.

If your incremental cost per KWh is 15 cents, each watt used (if used 24 hours a day) costs \$1.30 per year.

If a desktop computer is left on all the time, and its sleep mode is ineffective, it could cost \$260 more per year than using a laptop.  Likewise enabling sleep mode could come close to saving that same \$260 in some cases.

Just for fun remember that a 100 watt incandescent light bulb if left on also costs \$130 a year.  Replacing just one of those with an LED bulb using 15 watts saves \$110 a year (if left on 24 hours per day).

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• #2529858

You can determine your PC’s maximum power consumption by going on line, entering the computer’s name + specifications.

Using this approach, I have determined that the HP ENVY Desktop – 795-0050 that I am using shipped with a 400 W SFF (Platinum) Full range 115V/230V power supply with 92% efficiency.

When I open the app PowerPanel Personal I see that the PC, modem, router and one monitor are drawing 116 watts as I write this post.

PowerPanel also indicates that the system has consumed 274.0 Wh since midnight and that, on average, that level of power consumption has contributed 0.139 kg of CO2 to the atmosphere.

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• #2529866

I was about to recommend the Kill-A-Watt device but Cybertooth got there first. The device can also provide a readout of total kilowatt hours for an extended period which should be more informative as watts alone will vary somewhat. The Kill-A-Watt can be used to check many other devices at no more than 135 volts max. Even provide frequency (Hz) for you portable gasoline electric generator! Costs about \$30.

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• #2529926

My formula is ‘can I afford it = leave on… if not, switch off.

I like easy questions and answers. 🙂