Be Quiet! PSU vampire power

[Bidule0hm]

Especially because the thing must have power factor correction.

And even more because it's not inductive, it uses rectified DC so what you have is current spikes when the caps charges...

 

[cyberjock]

If that 14W is with it plugged into the motherboard and other components, I'd call that nearly normal. On the other hand if nothing is plugged into the PSU, then you've likely got problems.

You need to remember that even with the power off, certain components are still on. Most notably the IPMI and power circuits.

 

[MrToddsFriends]

Just for comparison: I see a power consumption of 5W with my system when shut down (PSU power switch on, IPMI running).

Mainboard: Supermicro A1SAi-2750F
Power supply: be quiet! STRAIGHT POWER 10 400W (BN230)
Power meter: ELV Energy Master Basic 2 (German website: http://www.elv.de/elv-energy-master-basic-energiekosten-messgeraet-1.html)

I'll do another measurement with the PSU switched off during the next weekend. I remember that I read somewhere (maybe in the german computer magazine c't) that it's not advisable to put a PSU into operation with no load connected at all (but I can't remember the reason).

 

[Ericloewe]

I'll do another measurement with the PSU switched off during the next weekend. I remember that I read somewhere (maybe in the german computer magazine c't) that it's not advisable to put a PSU into operation with no load connected at all (but I can't remember the reason).

That's not true.

What old PSU designs have trouble with are unbalanced loads. Modern designs use DC-DC converters for the minor rails, so asymmetric loads are no problem at all.

 

[Bidule0hm]

I never saw a PSU, old or new, failing because it was powered unloaded, it would be a very big design fault otherwise...

NB for everyone: if you can post the model of the powermeter you used to do the measure each time you post a result it would be helpful because not all powermeters are equal.

 

[AndyFL77]

But the problem is actually the meter
It is an electronic characteristic of the components making old meters unable to get a good reading
There are capacitors and other circuits even before the PSU switch so there is a 0.1W power draw
Powered of a new PSU connected to a new motherboard should be below 1W
Will not apply to servers :)
Get another meter
That one is not good for this job

To put this thread to bed, tres_kun was absolutely right. It was all down to the meter. I got an Energenie to replace my old PM230 and retested everything. The stats are now:

• PSU off 0W
• BMC on 4.4W
• FreeNAS running 45W
• FreeNAS idle 29W
• Startup surge 68W

Very happy with by Be Quiet! BN180. As punishment I have realised that the cost of the new energy meter is higher than 2 years’ worth of running my FreeNAS box. Thanks for your comments everyone.

 

[jgreco]

Very happy with by Be Quiet! BN180. As punishment I have realised that the cost of the new energy meter is higher than 2 years’ worth of running my FreeNAS box.

Naw. You've mistaken acquiring a new fun toy for punishment.

The *punishment* will be when you start getting all OCD about wandering around measuring power usage on this and that.

 

[AndyFL77]

Naw. You've mistaken acquiring a new fun toy for punishment.

The *punishment* will be when you start getting all OCD about wandering around measuring power usage on this and that.

The funny thing is that I do have a spreadsheet that lists consumption for every appliance in my house and yes it’s going to get refreshed. There’s no point spending money on energy saving unless you know where the most consumption is.

 

[jgreco]

The funny thing is that I do have a spreadsheet that lists consumption for every appliance in my house and yes it’s going to get refreshed. There’s no point spending money on energy saving unless you know where the most consumption is.

See? Called it, didn't I. <== experienced toy buyer.

 

[MrToddsFriends]

That's not true.

What old PSU designs have trouble with are unbalanced loads. Modern designs use DC-DC converters for the minor rails, so asymmetric loads are no problem at all.

The stuff I vaguely remembered is also described here:
http://reprap.org/wiki/PC_Power_Supply#Base_Load
http://reprap.org/wiki/PC_Power_Supply#Minimum_Load

Something related I nearly forgot over the years: To turn on an ATX PSU takes more than just to plug it into mains and to toggle the mains switch (one of the differences to an old AT PSU):
http://reprap.org/wiki/PC_Power_Supply#Turning_the_supply_on

But I must admit that I don't know what "asymmetric load" does mean in this context. I got lost in descriptions of three phase power distribution ...

 

[Ericloewe]

got lost in descriptions of three phase power distribution ...

Nothing related at all. This is DC, there are no phases. ;)

What I meant was loading +5V disproportionately to +12V or some similar cases.

 

[tres_kun]

My startup consumption is about 270W
And the most surprising thing after using the meter on my stuff
My bookshelf speakers were using 10W while doing nothing
By just being on they were using 10W
And other bluetooth speakers i have playing music on low volume were using 2W

 

[anodos]

Naw. You've mistaken acquiring a new fun toy for punishment.

The *punishment* will be when you start getting all OCD about wandering around measuring power usage on this and that.

I thought *punishment* happens after the spouse notices you've bought a new toy because you're wandering around the house measuring things. :D

 

[jgreco]

I thought *punishment* happens after the spouse notices you've bought a new toy because you're wandering around the house measuring things. :D

Naw, that leads to divorce, which leads to more money to spend on toys.