PSU Power and Heat: Understanding the Relationship

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In summary: Sounds like a neighbor hasnt yet noticed the extension cord running from his outdoor power outlet.Heh, no... The setup uses 4 separate circuits. Sounds like you have a lot of electrical equipment. Are you mining bitcoins?I did read an article about an IT guy/gal at a community college who set up the computers in the computing commons to all mine bitcoins. He/she was caught when the electric bill came in.Keep in mind that a PSU rated at 800W simply means that it can supply up to 800W if the components of the computer demand it. It doesn't mean that it will be pulling 800W all the time. It would be extremely uncommon for
  • #1
TSN79
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If my PSU is 800W and it runs at full power, does that equal a 800W heater standing in my room, or does just some of it turn into heat?
 
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  • #2
Is your power supply nearly as hot as a toaster?
 
  • #3
Computer power supplies are tricky in that I don't think they are very accurately rated, but if it were accurately rated at 800W and were running at full power, it would generate probably 270W of heat (at about 75% efficiency) and whatever it was powering would generate 800W of heat.
 
  • #4
There are little gadgets that you plug into the wall and then plug you appliance into the gadget. It then displays how many watts are actually being used. The "Kill A Watt electricity usage monitor" is one of those. Someone at the local public library got the idea of buying a few of those and making them available for checkout. Since the average person probably only needs one of these for a couple of hours that spreads out the cost of purchase over many many users. Perhaps you could coax your library to do the same.

I was a little surprised when I went around the house measuring power consumption of each of the appliances, computers, monitors, routers, cable boxes, modems, etc.

Almost all the watts going into the computer turn into electromagnetic radiation, heat, rf, light, they just vary in wavelength. If the power supply is less efficient then more of the watts turn into long wavelength infrared (heat) inside the power supply and less of the electricity is passed to the computer itself before being turned into heat.

I suppose the only exception might be the fans turning electricity into moving air rather than directly into heat. If you have a UPS or other rechargeable batteries then there can be a small amount of electricity temporarily turned into chemical energy before then being turned into heat when you use the battery power.
 
  • #5
I have one. When plugged into my computer, which is relatively advanced, has a lot of hard drives and a 500W PSU it gave me:

140W during boot
120W when idle in windows
190W during a game w/3d graphics.
 
  • #6
russ_watters said:
I have one. When plugged into my computer, which is relatively advanced, has a lot of hard drives and a 500W PSU it gave me:

140W during boot
120W when idle in windows
190W during a game w/3d graphics.

I have one too. I melted it a bit running too many watts through it... lol

This is what I was measuring though,
wTees.jpg


Lots and lots of watts so of course lots and lots of heat. The whole setup is between 3-4 kW IIRC. So basically its a 3.5 kW heater. Great in the winter, tough to keep under control in the summer.
 
  • #7
ModusPwnd said:
I have one too. I melted it a bit running too many watts through it... lol

This is what I was measuring though,
wTees.jpg


Lots and lots of watts so of course lots and lots of heat. The whole setup is between 3-4 kW IIRC. So basically its a 3.5 kW heater. Great in the winter, tough to keep under control in the summer.

Wow. Other than a heater what are you using that for?
 
  • #8
$$$$ (mining bitcoins) Its been real profitable so far, I have very cheap electricity. The market is changing though and I will be selling it off soon.
 
  • #9
Sounds like a neighbor hasnt yet noticed the extension cord running from his outdoor power outlet.
 
  • #10
TSN79 said:
If my PSU is 800W and it runs at full power, does that equal a 800W heater standing in my room, or does just some of it turn into heat?

All the energy IS dissipated eventually as heat in the room, yes. Some from the power supply itself. The rest from the computer it is powering.
 
  • #11
Chronos said:
Sounds like a neighbor hasnt yet noticed the extension cord running from his outdoor power outlet.

Heh, no... The setup uses 4 separate circuits.

I did read an article about an IT guy/gal at a community college who set up the computers in the computing commons to all mine bitcoins. He/she was caught when the electric bill came in.
 
  • #12
Keep in mind that a PSU rated at 800W simply means that it can supply up to 800W if the components of the computer demand it. It doesn't mean that it will be pulling 800W all the time. It would be extremely uncommon for a modern system to pull more than about 100-150W during normal usage, perhaps up to a few hundred watts under heavy usage.
 

1. How does a PSU generate heat?

A PSU (power supply unit) generates heat through the conversion of electricity from the wall outlet into usable power for the computer components. This conversion process produces heat as a byproduct, similar to how a toaster or hairdryer generates heat.

2. Is it normal for a PSU to feel hot to the touch?

Yes, it is normal for a PSU to feel warm or hot to the touch. As mentioned before, the conversion process of electricity into usable power produces heat. However, if the PSU is extremely hot to the touch or emitting a burning smell, it could be a sign of a malfunction and should be checked by a professional.

3. Can a PSU overheat and cause damage to other components?

Yes, if a PSU is not functioning properly or is overloaded, it can overheat and cause damage to other components in the computer. This is why it is important to use a PSU with the appropriate wattage for your computer's needs and to ensure that the PSU is well-ventilated.

4. How can I reduce the heat generated by my PSU?

One way to reduce the heat generated by a PSU is to make sure it is not overloaded. This means using a PSU with the appropriate wattage for your computer's needs and avoiding using extension cords or adapters. Keeping the PSU well-ventilated and free of dust can also help reduce heat generation.

5. Are there any safety precautions I should take with a PSU that generates heat?

Yes, it is important to handle a PSU with care as it can become very hot. Make sure to unplug the PSU before cleaning or working on your computer to avoid any electrical shocks. Keep the PSU well-ventilated and avoid covering it with any objects that could block airflow.

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