# Building an energy efficient computer/workstation?



## MannDude (Mar 8, 2015)

Has anyone here gone through the trouble of building a PC to be as energy efficient as possible? I'm trying to find resources online, rather it be a parts calculator or what-have-you and having some difficulty. Working from home, my computer is the largest consumption of energy in my home and I'm wondering how efficient it could be, if it'd be worth the trouble, or if they even produce hardware that takes this into consideration.

I don't do anything CPU heavy. No gaming. Memory usage normally is around 4GB~ but spikes to 6GB or so depending on what all I'm doing. Has gone higher but that's when running an excess of stuff. Graphics don't need to be fancy, right now running a 2GB fanless card and it does what I need it to do. The i5-2400 doesn't really get utilized, could scale back on that as well.

As long as I can run Thunderbird, Firefox, Chromium, gEdit, Calculator, Hip-Chat, and Skype all at once I'm pretty much good to go.


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## tonyg (Mar 8, 2015)

Definately start out with the biggest energy waster...the power supply.

Get an efficient power supply at:

http://www.mini-box.com/s.nl/sc.8/category.13/.f


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## HalfEatenPie (Mar 8, 2015)

Without going into specific research, how about the Atom C2750?  

The base board itself is 360 dollars.  Just need some RAM, you already have the video cards (assuming you'll be moving the video cards from your previous setup), get four 2 GB DDR3 sticks of RAM (20 dollars each, 80 dollars total) or a single 8 GB RAM Stick for 80 dollars (you'll lose channel transfer speed if you go this route).  Assuming reusing hard drives and case (so buy a new get a low powered power supply.  It's around 500 dollars (i'd assume at least) for the new computer but it'll use so little power.


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## WebSearchingPro (Mar 8, 2015)

These are two setups I've done.

 

Celeron J1900 (2.0GHz)

8GB Ram

120GB SSD

Antec ISK110-VESA

 

Wattage: 15-20

 

The nice thing about this build is the quad core processor that is enhanced by the fact that the system is completely silent due to the passively cooled nature. 

 

----

 

Chromebox M004U

Dual core 1.4GHz

6GB Ram

120GB SSD

 

Wattage: 5-10

 

I bought a chromebox for $114 recently, threw in some ram, a bigger SSD and installed the coreboot firmware to allow installing of normal linux OS and removing google bits from the boot. This little machine is rather impressive, I have tons of stuff open ranging from pycharm to x2go and 20+ browser tabs spread between firefox and chrome and it runs like a champ as I write this.

 

 

----

 

Comparison:

i7-3550

32GB Ram

AMD 6770

120GB SSD

1TB HDD

 

Wattage: 100-130

 

Of course none of these are scientific values - I had a kill-a-watt and plugged stuff into it at some point or another.


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## drmike (Mar 8, 2015)

I did this sort of things years back when I was planning on running off grid (i.e. no mains power).

Biggest culprits of power burn are:


 Leaving your PC on 24/7.
Thirsty CPUs with inefficient idle states
Video cards
Power Supply
Multiple Monitors

1.  Enable sleep / hibernate mode at minimum so the computer turns off when idle.   These states - some of them still consume power, but much less.

2. CPUs are a mixed basket.   Total socket wattage gives you just the maximum use at 100% utilization, it says nothing about non peak usage.  Most usage (unless your browser is sitting there with gazillion tabs loaded with JScripple and Flash) is non peak (i.e. most people are 90%+ active time use with non peak).  You want a CPU with good idle states that whacks down the power in a big way.  

3. Video cards, add on cards are just pigs.  Try sticking to integrated on board video.    If you require a second monitor look at alternative video options such as the USB video cards (I haven't used them since eons ago when interested support in Linux wasn't very well developed --- I suspect today they just work)   --- Looking at $25~ for such a video card and it won't drive some crazy gaming, but fine for everything else.

4. Power supply -  people really berate power supplies.  Truth is, they use to be way more inefficient.  You want something ideally 95%+ efficiency.

Here's the pickle though, power supplies tend to be made for mains power, for AC.  AC is on grid wired to the utility.  All the components in a PC however are DC.  Running commonly 12V, 5V, 3V depending on what component inside your computer.  Converting AC to DC is lossy even with the best PSU.  

Try bypassing that whole stupid loss and get a DC-DC power supply.  If you are running off grid, you can direct connect DC from batteries, controller, panels directly to a DC power supply, given at the same voltage.  

PicoPSUs are one such solution I've used in years past. This is a 160 watt version:

http://www.amazon.com/Mini-Box-picoPSU-160-XT-Power-Mini-ITX-Supply/dp/B005TWE6B8

You will need to match the wattage to your build.   You can power the Pico's on grid with an AC-to-DC wall block like you find used with many computer components.

Next, monitors don't run on magic.  LCDs today are more efficient than displays in the past, but if you are pushing big monitors, still going to eat up power multiplied by number of displays.   You need to determine what the displays you have or want to use consume and see how they compare to efficient models.  Might make sense to run roughly 20" monitors at this point and without too many features.   You should have power savings enabled to turn the monitors off after something aggressive (i.e. 30 seconds to 1 minute), maybe longer if your use has you idly watching things.  However, never much more than say 10 minutes in my opinion.

You are going to need, and everyone should have one of these if you are on mains grid:

http://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU

That allows you to plug rate test and see electric usage of your gear on piece by piece basis by directly connecting a gear piece thereto, or you can take a whole strip with your setup and plug into for total build.   It does on-time cumulative tracking also so you can see your usage over a day or week.


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## drmike (Mar 8, 2015)

WebSearchingPro said:


> These are two setups I've done.
> 
> 
> 
> ...


There are interesting builds and clearly speed improvement and more tolerable since running SSDs.

Are you aware of either platform, elsewhere or you personally driving say 2 monitors with such?


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## drmike (Mar 8, 2015)

There are a bunch of other things that come to mind when doing an efficient build or rebuild these days.

Modem   ]

Router    ]

Switch    ]

Wifi         ]

... These three no one looks at.   Big issue with this stack is normally they are 24/7/365.   If doing solar/wind/alt power, no way to sensibly run these 24/7, or anything else unless you have a big system which is cost prohibitive at scale (watts really add up on 24/7 run time).

In fact I haven't watt tested my current gear at all, but going to (glad for this thread).  I know my 24 port switch is a pig, but it's managed and gets good throughput on a high performing fabric.  Trendnet makes alright desktop gigabit switches with power savings functionality baked in (5 and 8 port models). 

Modem and router  ---- likely best in a combo unit that bundles both and throws the wifi in and a few ports out back of switching.   I can't do that with my setup and size of network or I would.

Storage  ---  you can go in chasis storage which I do on top of runtime SSDs.  Downside in efficiency model is that if you do anything like DLNA or serving content to other things (TVs, tablets, phones, etc.) that will require computer to be on while doing other things.   Really can ruin power off savings.

There are slews of ARM based boxes with various interfaces for tethering storage (usually and most commonly USB).  Raspberry Pi is one such solution Mann already has.   Tethering the Pi to 1 or 2 USB external big drives might be the best mix of watts and isolation.  I do something similar with repurposed Pogoplugs to drive everything in my world.   It isn't high performance, but it works very well for a single user world where you aren't needing to say edit video or push masses of data right now all at once.  Now assuming with such ARM device, running Linux that the external drives are rightly config'd, support, and using spin down modes (recommend using 2.5 inchers that are designed for such cycling - desktop drives historically get beat up by power ups and downs).  You will save on watts by having your storage on 2.5" drives regardless of where they are.

Other thing related to much of this is your AV system.  Driving a 32" TV, especially a Smart model gets spendy on power if running that during most of your waking hours and especially during work.  Resizing to perhaps a high resolution tablet could save quite a bit.  Then again, I've never been fond of the whole display thing where humans have low res, but nearly right sized heads.  TV isn't that surreal and submersive.... I like the whole tunnel vision  triangle where I have the widest view looking forward at a narrower object.

If you run speakers and amp, more optimization there. That can really eat watts when on and unused.

When doing a rebuild like this, pieces often aren't so common.  All are mail order.  So you have to take proper steps to stock spares yourself.  Next time out to market finding pieces might yield little to no matches and waiting around for the Fedex or mailman to drop your package just sucks.

When I did my power efficient builds years back, did mini itx stuff.  Made sense then.  Quickly determined high fail rate on AC-to-DC wall warts, so I bought several spares.   Router combo unit, similarly, I picked another one up and config'd as a hot spare since I had everything going through there (wifi + internet + switching).


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## MannDude (Mar 8, 2015)

Thanks everyone. This is all sort of new to me and not something I spent much thought on before. But I'd like to reduce my usage where possible, and my PC is a big consumer of power. I bought a Kill-A-Watt meter to measure the useage of a powerstrip that has my PC, two monitors, and speakers plugged into it.

Apologies for the weirdly cropped photos. The power outlet is at like a 45 degree angle near an intake for the furnace so I rotated the images and tried to crop out the collection of dust that was very visible with the flash... But you get the point.

I'm not 100% certain on what all of this means if I am being honest. I need to read up more on electricity but the results are shown below. I'm starting to turn my PC off at night and have my monitors turning off after about ten minutes as well for the time being.


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## drmike (Mar 8, 2015)

MannDude said:


>


So those two combined mean this:

3.61 Kwh consumed in 40 hours and 19 minutes.

Let's round for easy math:

3.61 KwH = 3610 watts

40 hours

3610 / 40 = 90.25 watts per hour if usage is uniform.  In computing it never is unless running something fully 100% or at baseline consistently idle.

If we do the math for a month based on the hourly figure:

91 watts (rounded up)  x 720 hours in a month = 65520 / 1000 = 65.52 Kwh a month.

This 90-99 watts, is that just your PC into the Kill-a-Watt?   Not including monitors, wifi, router, switch, other peripherals right?


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## WebSearchingPro (Mar 8, 2015)

drmike said:


> There are interesting builds and clearly speed improvement and more tolerable since running SSDs.
> 
> Are you aware of either platform, elsewhere or you personally driving say 2 monitors with such?


I've used both systems with dual monitors, it does work. The wattages listed do not include the monitors, due to high variability. 

My Dell S2340M 23" IPS display has the best wattage of all my monitors at ~16.5 Watts on a full white screen.


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## MannDude (Mar 8, 2015)

drmike said:


> This 90-99 watts, is that just your PC into the Kill-a-Watt?   Not including monitors, wifi, router, switch, other peripherals right?


Power strip that contains two monitors, PC, and speakers for PC.


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## zzrok (Mar 8, 2015)

Don't forget to look into the speakers on their own.  Some systems have rather inefficient amplifiers that suck a lot of power even with no audio output.  Same can be said of the monitors, but usually less so.  Most of them have low power draw when in standby, but measure independently to know for sure.


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## drmike (Mar 8, 2015)

WebSearchingPro said:


> I've used both systems with dual monitors, it does work. The wattages listed do not include the monitors, due to high variability.
> 
> My Dell S2340M 23" IPS display has the best wattage of all my monitors at ~16.5 Watts on a full white screen.


How are you driving 2 monitors on those systems?  Do those natively support dual monitors with the integrated video on board?  What sort of connectors from those to your monitors? HDMI?


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## KuJoe (Mar 8, 2015)

My advice if you want to cut your PC's energy usage to barely anything, go get a Raspberry Pi 2 and grab a cheap yearly KVM (or even OpenVZ if you don't mind OpenVZ) and use the RPi2 as a thin client to your "desktop in the cloud". 

I have a dedicated server I use for my Win7 desktop but for normal usage my 256MB BuyVM KVM with Server 2003 gets the job done also.


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## drmike (Mar 8, 2015)

MannDude said:


> Power strip that contains two monitors, PC, and speakers for PC.


So if averaging 91 watts for everything there mentioned = full system.  That's not too bad.

Factoring this to cover a work day 8 hours plus an hour before and after = 10 hours a day.   10 x 91 = 910 watts.

To cover that with off grid power (i.e. solar usually) you would need:

910 / 4 = 227 watts+ of solar with 4 hours of sun for 1-to-1 ratio, which you can't sustain really since clouds and stuff happen. So you'd be doing, meh, 250 watt panel minus losses to cover and another panel to bank energy for cloudy and less usable times.   125 watt panel on top will ideally suffice.  375 watts of solar total.  Maybe less if you invest in motorized tracker since you will get more watts a day using such.

Battery needs to do ummm 40AH just for 1-to-1 coverage.   You want minimal draw or batteries will get abuse worn quick.  So 200AH+ in batteries.   All this is based on 12V.   Common to bump combo voltage up to combat wireline losses and such. So math wise it's simple 12V @ 200AH = 24V @ 100AH = 48V @ 50AH.   Batteries usually are 2V, 6V, or 12V.    Cost effective are 6V and 12V and wiring them for wanted voltage (just simple self wiring schematic).


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## MannDude (Mar 8, 2015)

KuJoe said:


> My advice if you want to cut your PC's energy usage to barely anything, go get a Raspberry Pi 2 and grab a cheap yearly KVM (or even OpenVZ if you don't mind OpenVZ) and use the RPi2 as a thin client to your "desktop in the cloud".


Do tell me more. 

Do you just use the Pi to connect to a remote VPS with x2go or VNC or something?


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## KuJoe (Mar 8, 2015)

MannDude said:


> Do tell me more.
> 
> Do you just use the Pi to connect to a remote VPS with x2go or VNC or something?


Since my remote boxes are Windows I use FreeRDP on my RPi2. The experience is great and in all honesty it's hard to tell that you're not running the OS locally unless you're trying to watch movies (in which case I would switch to my ODroid C1, tablet, smartphone, or netbook to watch the videos locally). The thing I love about it is I get the fast 1Gbps ports for downloads (downloading ISOs and mounting them to an IPMI/DRAC/ILO is so much better than trying to do that on my home connection) and if I need to run a script or something that will run for hours or days I don't have to worry about power or network outages at my apartment since everything keeps running on my remote desktop. I can start working on something at work and pick up exactly where I left off when I get home with all of the windows and tabs open.

Basically I don't need to take my laptop with me anywhere and I can RDP from my Android smartphone, Android tablet, or my netbook which just has a base install of Crunchbang and FreeRDP with my VPN settings already. I use my laptop still for gaming and watching movies but I don't think I'll ever get a desktop computer ever again and my daughter's PCs will all be thin clients connecting to either Linux or Windows VPSs remotely (this way if she clicks on the wrong thing our local network is still safe or if he IP gets leaked online the best they can do is fine out where the VPS is hosted).

EDIT: I did a nice write up in the RPi2 thread here about my experience using the RPi B+, RPi2, and ODroid C1 as desktop replacements and thin clients and the RPi2 had the best experience as a thin client, even better than using it as a desktop replacement.


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## trewq (Mar 8, 2015)

@KuJoe does that mean you can only use a single monitor?


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## MannDude (Mar 8, 2015)

trewq said:


> @KuJoe does that mean you can only use a single monitor?


Good question... I didn't think about that. I feel much too constricted on a single monitor for work. Too much going on and even with two monitors I find myself having to tab through windows/applications often.


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## trewq (Mar 8, 2015)

MannDude said:


> Good question... I didn't think about that. I feel much too constricted on a single monitor for work. Too much going on and even with two monitors I find myself having to tab through windows/applications often.


I've been using 2x 19" 4:3 at work... It's unpleasant. I can not use one monitor anymore and be productive.


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## KuJoe (Mar 8, 2015)

trewq said:


> @KuJoe does that mean you can only use a single monitor?


I never thought of that. I only have a single 27" monitor at home so I never looked into a multiple monitor setup with my devices.


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