forum.excito.org

I am measuring power consumption of my B3-Wifi on the primary (230V) side of the PS with a good power meter and observed a strange beheaviour:

1. under normal operation it consumes 10 - 12.5 watts depending on CPU-load. When totally idle it is 9.8 watts.

2. when HD unloads its heads and goes "idle" consumption drops to 7.9 watts. When HD finally spins-down and goes "standby" consumption drops to only 5.6 watts.

3. when I shutdown the B3, no matter if by software (shutdown -h) or with the power-button, the device will end up with 6.1 watts power consumption constantly - for ever!

That is more then booted with disk spun down - is there any solution?

With kind regards,
Ingo

Pull the plug?

indeed. THe power is consumed by the power convertor. All convertors consume about 5W when nothing is connected. And before anyone gets upset, go round your house and count the number of plugged-in phone chargers, idle TV and stereos, etc etc. You unplugged those too right?

I'm not sure of the specifics but isn't there an EU law that says any new device should consume <1W on standby?

Yeah the '1W initiative'. Not sure what the status is on that

Hi all,

We are aware of this issue. Actually in the B3 case it's a nasty bug in the bootloader which makes it not go to CPU sleep mode when idling and waiting for a boot (it looks as a stupid busy-wait using 100% cpu, but I'm not sure). A fix is scheduled but not yet started.

However, I have never seen so high figures, I measure about 3-4W when shut down. A warning - when measuring power with standard "digital" power meters, they usually get fooled by switched adaptors under low load, since they then show a non-standard behaviour (inductive and noisy load). I always use an old-fashioned spinning-disk power meter - they are unfoolable. See picture.

The 1W initiative is valid now - but doesn't formally apply to us since B3 does not have proper on/off modes. B3 is on, or unplugged, that's the idea. A server is normally not off, it's built to be on 24/7. In any case we should of course fix this, it's not very nice.

Many thanks für your explanation, Johannes.
My concern only was that there is still something up and running and "pulling the plug" might cause some damage to the system.

The B3 ist craftet very well and I like it much, especially because of the free and open source software - an almost standard Squeeze! Hope you will be able to fix that uBoot-issue as well,

Ingo