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Re: 1 Watt server challange!

Posted: Wed May 01, 2019 5:47 am
by rpdom
whiteshepherd wrote:
Wed May 01, 2019 4:03 am
drgeoff wrote:
Tue Apr 30, 2019 9:50 am
An ohm meter measures resistance.
Most ohm/multi meters can also measure voltage and current draw if you didn't know....
Most multimeters/voltmeters will also measure current and resistance, I think you mean.

It is very rare that you will find something called an Ohm meter that does anything other than measure resistance, they tend to be specifically for measuring resistance with high accuracy.

Re: 1 Watt server challange!

Posted: Wed May 01, 2019 8:40 am
by Gavinmc42
What ever the minimum serving time is, ie 1ms them the current sampling frequency needs to be about 3KHz or more.
Multimeters are not fast enough as they use a dual slope ADC which is much slower.

Super caps have charge and discharge voltages that will vary if you want to smooth out the current.
You will have smoothed out the current but then the voltage will vary ;) .

ADC's faster than 5KHz are easy enough to find.
You need to measure current at 100% server usage as that will determine the maximum power.
A lower duty cycle is just a bonus.

If the Ethernet chip is actuve and waiting it still draws current.
About 200ma at 3v3 ~ 600mw.

Is there a way to have a low power Ethernet sensor/chip that wakes the Pi up when it gets a packet addressed to itself?
Low power IoT on Ethernet?
Perhaps this new two wire Ethernet standard they are using in cars?

Re: 1 Watt server challange!

Posted: Wed May 01, 2019 11:22 am
by PiGraham
Gavinmc42 wrote:
Wed May 01, 2019 8:40 am

Is there a way to have a low power Ethernet sensor/chip that wakes the Pi up when it gets a packet addressed to itself?
Low power IoT on Ethernet?
Perhaps this new two wire Ethernet standard they are using in cars?
Not directly, since the Pi has no low power modes and doesn't support WOL. If you used a microcontroller you could connect an Ethernet interface that would wake the uC by interrupt on a magic packet and use that to turn on power to the Pi.
Here is an Instructable using an Arduino to act as a WOL power switch.
https://www.instructables.com/id/NAS-Ov ... on-for-NAS

The datasheet for the Microchip ENC28J60 indicates 120mA @3.3V to keep the Rx & Tx powered to allow detection of the wakeup packet. So 396mW for the WOL plus regulator overhead and whatever the uC needs in it's lowest power wakeable state. For ATTiny85 that's less than 1uA I think.(But measuring such small currents is tricky).

Re: 1 Watt server challange!

Posted: Wed May 01, 2019 3:25 pm
by hippy
PiGraham wrote:
Wed May 01, 2019 11:22 am
Not directly, since the Pi has no low power modes and doesn't support WOL. If you used a microcontroller you could connect an Ethernet interface that would wake the uC by interrupt on a magic packet and use that to turn on power to the Pi.
The Pi could be woken up by detection of any ethernet packet addressed to it. That would have it 'always available' even if not 'immediately responsive'.

The first challenge would be to find an ethernet interface which can do that, receive all packets, set a signal whenever one for the Pi was received, which would be used to wake the Pi up if sleeping. It would ideally need to buffer packets for the Pi while it was waking up.

There are some ethernet interface chips which have pretty low consumption figures and, coupled with a low-power micro, might provide an option for this 'ethernet front-end'.

The second challenge would be sleeping the Pi and waking it up quickly enough. It is entirely possible for the Pi to disconnect its own power, go to zero current draw. It then comes down to what's a fast enough boot time, and how long it should stay awake ready for another packet. Pretty fast boot times can be achieved which I think would be good enough.

There are some articles on reducing ethernet power and where the problem areas are, including -

https://www.eenewspower.com/content/pow ... -operation

That illustrates why simply putting the Pi behind a smart switch, hub, router or anything else won't reduce the power to zero simply because it's not having any packets passed to it. And, even if it were possible to reduce Pi ethernet consumption to zero, I would expect the power consumption of whatever is doing that to be included the total consumption figures. Otherwise it's just hiding consumption away.

It is possible to have an entirely direct ethernet cable connection, that is, no magnetics on the Pi side. But I'm not sure that would be acceptable if it can be made to work.

Re: 1 Watt server challange!

Posted: Wed May 01, 2019 3:46 pm
by PiGraham
hippy wrote:
Wed May 01, 2019 3:25 pm
PiGraham wrote:
Wed May 01, 2019 11:22 am
Not directly, since the Pi has no low power modes and doesn't support WOL. If you used a microcontroller you could connect an Ethernet interface that would wake the uC by interrupt on a magic packet and use that to turn on power to the Pi.
The Pi could be woken up by detection of any ethernet packet addressed to it. That would have it 'always available' even if not 'immediately responsive'.

The first challenge would be to find an ethernet interface which can do that
I linked one.
The Pi can't do it on it's own. It needs something that can go into a wakeable powerdown and wake on a WOL interrupt from the Ethernet chip.
You have to turn the Pi off, vut the power, to get to a low power state. It has no micro-power sleep modes.

Re: 1 Watt server challange!

Posted: Wed May 01, 2019 3:51 pm
by PiGraham
hippy wrote:
Wed May 01, 2019 3:25 pm

That illustrates why simply putting the Pi behind a smart switch, hub, router or anything else won't reduce the power to zero simply because it's not having any packets passed to it. And, even if it were possible to reduce Pi ethernet consumption to zero, I would expect the power consumption of whatever is doing that to be included the total consumption figures. Otherwise it's just hiding consumption away.
Agreed, it seems unlikely it would make sense to get Pi consumption down to a minimum if you have a router always on anyway.

Re: 1 Watt server challange!

Posted: Wed May 01, 2019 10:33 pm
by stuartiannaylor
I noticed this the other day and thought of the thread dunno if of any use or interest, I dunno.

https://www.raspberrypi.org/blog/piserver/

Re: 1 Watt server challange!

Posted: Thu May 02, 2019 4:31 am
by ankith26
PiGraham wrote:
Wed May 01, 2019 3:51 pm
hippy wrote:
Wed May 01, 2019 3:25 pm

That illustrates why simply putting the Pi behind a smart switch, hub, router or anything else won't reduce the power to zero simply because it's not having any packets passed to it. And, even if it were possible to reduce Pi ethernet consumption to zero, I would expect the power consumption of whatever is doing that to be included the total consumption figures. Otherwise it's just hiding consumption away.
Agreed, it seems unlikely it would make sense to get Pi consumption down to a minimum if you have a router always on anyway.
Thats a good point. We have to give power to a router/modem... If that is counted, 1 Watt server would not be possible

Re: 1 Watt server challange!

Posted: Thu May 02, 2019 9:41 am
by hippy
If a PC has a direct connection to a Pi Server and the Pi uses less than 1W that would be okay.

If the PC connects to a router as does the Pi that would still be okay; the router is just for convenience, would not add to the consumption.

But if the Pi Server cannot draw less than 1W unless a router or other hardware is used, then the router or other hardware is a part of the solution and its consumption would have to be included.

The intent wasn't to make the challenge impossible to achieve but to avoid hiding consumption away. For example if a hardware device were added or the router firmware modified to not send link pulses to the Pi to reduce consumption the consumption used in doing that becomes a part of the solution, therefore must be included.

For example, if the challenge were 'the lightest car able to carry four people', it doesn't matter if that car is pulling a trailer, that trailer's weight wouldn't be included because it doesn't have to be there. If the trailer is there because it's carrying two people who would not fit in the car, the trailer is a part of the solution and does count.

Re: 1 Watt server challange!

Posted: Thu May 02, 2019 9:59 am
by PiGraham
hippy wrote:
Thu May 02, 2019 9:41 am
If the PC connects to a router as does the Pi that would still be okay; the router is just for convenience, would not add to the consumption.

Is that a reference to Piserver becasue that makes an x86 PC an integral part of a network of RPs that use the PC to server the boot image.
we have developed a new piece of software called PiServer. Use this tool to easily set up a network of client Raspberry Pis connected to a single x86-based server via Ethernet. With PiServer, you don’t need SD cards, you can control all clients via the server, and you can add and configure user accounts — it’s ideal for the classroom, your home, or an industrial setting.

https://www.raspberrypi.org/blog/piserver/
You would have to include the PC in the power figures . Of course one could try to get the overall consuption as low as possible, VIA's Epia CPUs are claimed to run on 1 Watt

Re: 1 Watt server challange!

Posted: Thu May 02, 2019 11:45 am
by hippy
PiGraham wrote:
Thu May 02, 2019 9:59 am
hippy wrote:
Thu May 02, 2019 9:41 am
If the PC connects to a router as does the Pi that would still be okay; the router is just for convenience, would not add to the consumption.
Is that a reference to Piserver becasue that makes an x86 PC an integral part of a network of RPs that use the PC to server the boot image.
It wasn't intended as such but, yes, that is an interesting case. If not booting from SD Card saves some milliamps, IMO whatever is allowing those savings to be made should be included in the total consumption figure. The Pi couldn't be booted without that 'other thing' so that becomes an integral part of the solution.

But an interesting question, if one had a number of Pi Servers, all booting from one PC; can the consumption of that PC be distributed equally between them all ?

An infinite number of Pi's would see PC consumption per Pi reduce to zero, so the PC consumption can effectively be discounted. If it can be discounted in that case, why not when there happens to be only one Pi, the other infinity-minus-one simply not connected yet ?

I think all we're doing though is proving how difficult it can be to define 'foolproof rules' and set absolute criteria for competitions.

It's probably best to see what people do come up with and then judge if there is any 'slight of hand' which caveats the solution. It is after all a challenge not a competition.

Re: 1 Watt server challange!

Posted: Thu May 02, 2019 12:55 pm
by PiGraham
hippy wrote:
Thu May 02, 2019 11:45 am

It's probably best to see what people do come up with and then judge if there is any 'slight of hand' which caveats the solution. It is after all a challenge not a competition.
Is anyone actually participating? Not even the OP as far as I can tell.
It all seems far too vague and aimless to me.

Re: 1 Watt server challange!

Posted: Thu May 02, 2019 11:58 pm
by whiteshepherd
Looks to me like people are participating and theory crafting.


Several months ago I used a Sata 2 USB adapter with a SP 240GB SSD and I was amazed how little power it took. I was thinking I could make useful server running at 1 watt. Don't know if it's going to be possible. But will be fun trying.

The plan for my attempt: I have a collocated server in Cleveland. I plan to create a local backup mirror of the web/php/mysql/IRCD/FTPD services I can redirect DNS in an outage. I also plan to install Samba for networking. This will create a network share for home files, and a media share for smart TVs and phones to play stored video files.

I going to use a SP 512GB SSD (was going to be 240GB but 512GB was on sale). UGreen Sata2USB (hacked to power Pi0W), and the Pi0W which will connect wireless tot he network. Based on past tests I hope to get everything under 1W power if possible.

After getting in the hardware I had to do a tiny bit of hacking. The Ugreen uses a 12V adapter which I wanted to power the Pi. So I soldered some wires to the + - of the power port.
Image

Next I drilled a hole for the wires to come through.
Image


Next I soldered the wires to a 12V to 5V USB buck converter. I then hot glued the adapter to the top of the Ugreen.
Image

Powered up the Pi0W boots off the fat partition on the SD card. However it loads it's file system off the SSD after initial boot.
Image


Initial tests for this system with Pi0W HDMI and lights set to off lowest power is 100ma at 12V (1.2 watts). However when CPU load goes up so does amps drawn averaging around 150ma. I see a couple of problems. Even with all those servers CPU usage will be below 1-2%. But there will be spikes at times. My biggest draw the 512GB SSD is twice the weight of the 240GB (gave to a friend) and I suspect the extra chips are pulling extra power which has pushed me over. There is a light on the 12V2USB adapter and the Ugreen as well as 2 LEDs inside the SSD not visible unless you open it up. I could clip the LEDs on the adapters (not sure I trust doing that to the SSD). But that still won't be enough power saved. I could try underclocking the Pi0W (if even possible) to see what that gains me. The other "big" power draw is the SDcard reader. SDcard reader is used at boot but not after that. I wonder if there is a way to manually turn it off to save power like you can the HDMI?
Image

I'm working on hitting 1 watt and keep my 512GB SSD. We'll see how it goes. If everything works according to plan, I will also put a little solar panel outside my window to feed a battery to run this server. Positive suggestions welcome. :)

Re: 1 Watt server challange!

Posted: Fri May 03, 2019 5:53 am
by rpdom
This won't save any power, but will save a wire. As you are using a Zero, feed the output of the buck directly onto the +5 and GND on the USB inside the USB2SATA adaptor. Then you won't need the cable between the buck and the Zero's PWR USB socket.

Re: 1 Watt server challange!

Posted: Fri May 03, 2019 10:48 am
by PiGraham
whiteshepherd wrote:
Thu May 02, 2019 11:58 pm

The plan for my attempt: I have a collocated server in Cleveland. I plan to create a local backup mirror of the web/php/mysql/IRCD/FTPD services I can redirect DNS in an outage. I also plan to install Samba for networking. This will create a network share for home files, and a media share for smart TVs and phones to play stored video files.

Excellent, a specification of sorts.

What uptime do you need? If you can schedule it to power on between certain hours to serve media and sync with your collocated server you could save a lot of power the rest of the time.

If it will be idle most of the time maybe a WOL config could work.

Re: 1 Watt server challange!

Posted: Fri May 03, 2019 6:04 pm
by HermannSW
OK, I powered Pi ZeroW with 3.30V from linear voltage regulator.
I connected VGA USB camera.
After bootup and ssh into the Pi 151mA were shown on idle operation.
Then I started gstreamer pipeline into fakesink (640x480, 30fps).

Code: Select all

$ gst-launch-1.0 -v v4l2src device=/dev/video0 !  jpegenc !  rtpjpegpay !  fakesink
To my surprise current rose to 253mA only, which is 0.835W, below 1W.
I need to get a real gstreamer pipeline going that streams with 25fps out of the Pi (udpsink?) to compare with ESP32-cam values:
Image

Re: 1 Watt server challange!

Posted: Tue May 14, 2019 1:14 am
by CCitizenTO
I figure the 1 watt challenge would have to be based on average consumption. Certain tasks will likely necessitate the need for going over 200mA consumption for short periods of time.

You could also save a large amount of power by sleep modes and using wake on lan stuff for when the server isn't being used.

Re: 1 Watt server challange!

Posted: Tue May 14, 2019 1:49 am
by Andyroo
CCitizenTO wrote:
Tue May 14, 2019 1:14 am
I figure the 1 watt challenge would have to be based on average consumption. Certain tasks will likely necessitate the need for going over 200mA consumption for short periods of time.

You could also save a large amount of power by sleep modes and using wake on lan stuff for when the server isn't being used.
Maybe a bit hard as the Pi does not have a WOL function :lol:

You could use a real time clock chip to wake the Pi as some HATs do but you do better to strip functions out of the OS to keep the minimal CPU use...

Re: 1 Watt server challange!

Posted: Sun Aug 25, 2019 11:18 am
by geev03
How about using a Pi4-4 ? :lol:
14 servers ( alpine in docker) running concurrently take less than 13W ! :mrgreen:

Re: 1 Watt server challange!

Posted: Sun Aug 25, 2019 11:27 am
by Gavinmc42
We have a winner :lol:
Would that be a server farm?

Setup up 14 different Pinets?

Re: 1 Watt server challange!

Posted: Sun Aug 25, 2019 11:36 am
by rpdom
What are those "servers" running. If just a bash prompt I'd discount them.

Re: 1 Watt server challange!

Posted: Sun Aug 25, 2019 12:08 pm
by geev03
rpdom wrote:
Sun Aug 25, 2019 11:36 am
What are those "servers" running. If just a bash prompt I'd discount them.
They are all all 'busybox httpd' , all except one ( standard port :80) with non-standard 8080. 8081..xxxx ( busybox httpd -p xxxx ).
The servers are doing a bit of intensive processing, to get those (zoom able )dynamic maps from various GeoTags (latitude/longitude), too.

Re: 1 Watt server challange!

Posted: Sun Aug 25, 2019 2:43 pm
by hippy
geev03 wrote:
Sun Aug 25, 2019 11:18 am
How about using a Pi4-4 ? :lol:
14 servers ( alpine in docker) running concurrently take less than 13W ! :mrgreen:
Just to clarify; that's one Pi 4B 4GB running 14 virtual servers ?

The spirit of the challenge was however to run a single Pi at one watt, or less, or as low as possible.

Re: 1 Watt server challange!

Posted: Sun Aug 25, 2019 3:32 pm
by geev03
hippy wrote:
Sun Aug 25, 2019 2:43 pm

Just to clarify; that's one Pi 4B 4GB running 14 virtual servers ?

The spirit of the challenge was however to run a single Pi at one watt, or less, or as low as possible.
Yes, they are on a single Pi 4B 4GB and, as shown in the attached screen shot, there is still a lot more RAM and storage space to run another dozen or so such servers.
Though not in line with the 'spirit of the challenge' , this use case (64 bit tools on 64 bit hardware) can inspire many young minds in the school class rooms , code clubs etc 'in the spirit of the noble ideals' behind the creation of all types of R Pi models.

Re: 1 Watt server challange!

Posted: Mon Aug 26, 2019 1:43 am
by Gavinmc42
14+ servers :D
While not exactly what the original poster had in mind, I think this is a bigger win.
Using a Pi4 as a school Pinet server etc has been blown out of the water.

Some IT support guys will be interested or running for the hills :lol:
Racks of Picoblades filled with Pi4's?

This is more than just a Desktop Computer now.
I'm going to need more Pi4's :D

So what are the lowest powered servers?
Is there anything off the shelf lower?
Will the demand for Pi4B4 now explode as IT guys start needing racks of them?