A PSU that consumes the tineiest amount of power when turned off.

TigerUK

TigerUK

TigerUK

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1 Sep 2008
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554
my pc is in my signature, i thought the 530w psu was limite,d and then I got a power monitor today, amd found that it only uses 160W on idle, and around 250W-300w on boot. Crazy stuff.

I also found that when powered off the tower uses a constant 6-7w of power..

My monitor on the other hand uses a measly 15w of power when on and comepletely 0 watt when turned off, which is amazing because it's actually "awake" when powered down, because when the pc is turned on the monitor comes on automatically.

Why does the tower use 6w when turned off, where is that 6w get used? I know that the lan lights etc are on, and some of the mobo lights are obviously off as well.

What can I do to get the wattage down to as close to 0w as possible?
 
My HP server and mini itx build both pull around 15w when the system is off, my main pc I can't remember.
 
Some PSUs aren't particularly efficient at extreme low loads like power down state. Some PSUs state their power down state power draw. Your motherboard may also be to blame for drawing a lot of off power.

I went from OCZ SXS 600W 80Plus 80% efficient to a FSP Aurum 80Plus Gold 92% efficient and saw my off state drop from 5W to 2W. Idle drop from 166W to 148W. 100% Load from 422W to 365W. So the savings are quite palpable.

Your meter might not be all that accurate at low loads too. Your monitor probably does consume power of around 0.5W in standby, it's just your wattmeter can't detect it.

The other thing you have to consider is that the additional cost of a new PSU would take a good while to recover from your power savings so unless you need a new PSU anyway it's generally not worth it.
 
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I have a surge protector. Everything for my pc that requires power is plugged into that. Every time i switch of my pc at night, i switch the surge protector off and switch it off at the wall. Takes me less than a second :) im scared to just leave my pc off but still being powered on at the mains. My old monitor some how fried itself :\ so if you dont want it to use power when switched off, switch it off at the mains as well or flick the psu switch :)
 
marc1024 said:
I have a surge protector. Everything for my pc that requires power is plugged into that. Every time i switch of my pc at night, i switch the surge protector off and switch it off at the wall. Takes me less than a second :) im scared to just leave my pc off but still being powered on at the mains. My old monitor some how fried itself :\ so if you dont want it to use power when switched off, switch it off at the mains as well or flick the psu switch :)
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well a surge protector is supposed to protect you from spikes that can blow your system up..
 
You can buy a surge protector that has a master plug socket, you plug what ever you want into that one as your on/off.. say your monitor if you wanted your pc to fully turn off.. and all the rest into the other blocks, it detects when you power on the master plug and then allows power to all the other outlets. I actually cant remember what its called but this'd stop your problem. Either that or what I have under my desk is a surge protector with a switch on that I can turn off with my feet.. works the same :)
 
TigerUK said:
Why does the tower use 6w when turned off,
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A PSU is actually two separate supplies. One must supply power to the many components of a power 'system'. Other larger supply powers everything else. Some power ‘system’ functions may even monitor an NIC or modem so that the computer will power on due to detected activity. Also monitors the push button power switch.

Notice how little power any computer needs. But many are educated subjectively. Eyes glaze over with every numbers. Therefore many know only because hearsay has told them what to say. Some even buy 1000 watt supplies because hearsay said so. Your 530 watt supply was more than sufficient. However, it gets more interesting. Many 500 watt supplies are same as a 350 watt supply sold by more responsible companies such as HP, Dell, etc. Why different numbers? All depends on how and where a number is measured. Another example of unknown information when knowledge is provided subjectively.

You are doing what most do not do. You are including and demanding numbers.

A power system is more than just a PSU. A PSU contains two separate supplies. The efficiency of that '6 watt' supply is better with some manufacturers who provide numbers compare to others who sell only on irrelevant dollars and watts. Also more relevant is amperage for each voltage. Watts is a mostly irrelevant number. Because so many are only told watts, then a 250 watt computer can have a 1000 watt supply.

What can you do to reduce power? Alternative, other than replacing other computer parts, is to buy a PSU that actually provided efficiency numbers for that separate 6 watt supply. Most manufacturers will not do that. They are often selling to computer assembles who do not even know it has two power supplies. Providing less facts can cause more computer assemblers to recommend a supply.
 
westom said:
A PSU is actually two separate supplies. One must supply power to the many components of a power 'system'. Other larger supply powers everything else. Some power ‘system’ functions may even monitor an NIC or modem so that the computer will power on due to detected activity. Also monitors the push button power switch.

Notice how little power any computer needs. But many are educated subjectively. Eyes glaze over with every numbers. Therefore many know only because hearsay has told them what to say. Some even buy 1000 watt supplies because hearsay said so. Your 530 watt supply was more than sufficient. However, it gets more interesting. Many 500 watt supplies are same as a 350 watt supply sold by more responsible companies such as HP, Dell, etc. Why different numbers? All depends on how and where a number is measured. Another example of unknown information when knowledge is provided subjectively.

You are doing what most do not do. You are including and demanding numbers.

A power system is more than just a PSU. A PSU contains two separate supplies. The efficiency of that '6 watt' supply is better with some manufacturers who provide numbers compare to others who sell only on irrelevant dollars and watts. Also more relevant is amperage for each voltage. Watts is a mostly irrelevant number. Because so many are only told watts, then a 250 watt computer can have a 1000 watt supply.

What can you do to reduce power? Alternative, other than replacing other computer parts, is to buy a PSU that actually provided efficiency numbers for that separate 6 watt supply. Most manufacturers will not do that. They are often selling to computer assembles who do not even know it has two power supplies. Providing less facts can cause more computer assemblers to recommend a supply.
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you completely lost me there :o
 
A man can take over the world with such a speech

Its the peak power demand that causes people to buy 1kw power supplies. I had an i7 playing games on a 300w psu, devil is in the detail

The motherboard will draw power, thats more then enough to take 6w. Some bios options might help, mine has 'Green Lan' turns off empty slots.
Just flick the switch, my washing machine draws 15w when completely empty and it does that after every cycle. It is wasteful :/
 
quick update.

I got a corsair cx600

0w on idle... (proabably just less than 1w)

and 145 in idle.

That's a very good improvement on the tagan 530w.. (which I assumed was a high end brand).
 
arknor said:
never had a spike since i first owned a computer back in i believe 1998, never had a surge protector either...
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sometimes I feel like I'm living in the third world.. in the last 4 months.. I had 2-3 moments when the power abruptly shut down for 10 seconds.

I had one incident when the power went out from 1 in the morning to 12 in the afternoon.
 
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