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You don’t need a laptop to get an energy-efficient computer. Throwing together a PC nowadays doesn’t take a lot of effort. But if you want to build an eco-friendly desktop, it may take a little bit more knowledge. After a few failures and experiments How I Failed At Building An Eco-Friendly Next Generation Computer How I Failed At Building An Eco-Friendly Next Generation Computer Many said it was impossible. Even so, I finished building a highly efficient computer that didn't use fans. The PC's design emphasizes low-wattage, power efficiency, fanless construction, compact size and excellent processing power per watt.... Read More building my own fanless, highly efficient computer, I can share three builds of varying price and performance. These builds dispense with most moving parts and minimize the number of fans used.

There are effectively three kinds of component and configuration options when it comes to a power-efficient build:

  • Choosing a high-efficiency power supply;
  • Choosing components with low power-consumption;
  • Configuring your BIOS/UEFI to use less power.

Power Supply

Power supplies don’t convert from wall AC current to DC without a great deal of loss in power. The average power supply converts at 70% efficiency, meaning 30% wasted energy. However, two kinds of power supplies convert at over 90% effciency: PicoPSUs and 80+ Platinum rated power supplies. When choosing a build, either option presents a good choice. On the downside, many Platinum rated supplies cost a fortune and PicoPSUs are best mounted in special cases.

It’s also important to note that power supply efficiencies vary depending on load. Most supplies provide their greatest efficiency at around 50% maximum load. You may want to use a load calculator before choosing a power supply’s wattage.


Low-Power Components

The most power-efficient motherboards cost quite a bit and come with CPUs that have been soldered to the board, meaning if either the board or the CPU goes bad, the entire unit must be discarded. Personally, I prefer using lower-power CPUs combined with small form factor mini-ITX motherboards. Another component that makes a big difference in power consumption is adding a Solid State Drive. SSDs add amazing performance while consuming a tiny fraction of the wattage of a regular platter hard disk drive.



BIOS/UEFI Settings

There are a number of settings located in the BIOS (and its next-generation replacement, UEFI) that aren’t enabled by default that can have an noticeable impact on power consumption. Simply enabling the various power states on Intel boards (C1E and EIST) can reduce power consumption. You will want to enable them if they’re available on your motherboard. Some BIOS/UEFIs use colloquial language to enable lower power states, such as “eco-mode” or “low power mode”. Enable these, if available.

Desktop manufactures tend to leave these settings off for performance purposes. Higher frequencies tend to generate snappier performance. However, most users won’t notice the difference and you should definitely consider turning on your power-saving features.

Another BIOS/UEFI setting that can be turned on is EuP2013, which is the European standard for idle-state power consumption. If enabled, the computer will use no more than half a watt of power while powered off.

Tom’s Hardware published an excellent review of the various power-saving BIOS settings.

Build 1: $700-1000 Deluxe

Intel manufactures the best performing CPUs, despite some serious thermal design flaws Two Ways to Cool Down Your Defective Overheating Intel CPU Two Ways to Cool Down Your Defective Overheating Intel CPU Looking to purchase a Haswell or Ivy Bridge Intel CPU? A secret may change your mind. According to bloggers, Intel recently got caught using thermal paste on its CPUs and lying about it – the... Read More . In terms of performance-per-watt, Intel provides industry-leading power efficiency. In particular, Intel’s T and S series CPUs use between 35 and 65 watts. On a higher end build, I would prefer getting a Core i7-4765 or a BGA board, but these are so hard to get, the best option is an S-series CPU.

This particular build won’t knock any socks off. In fact, it remains relatively mid-range in terms of gaming and CPU performance. Even so, it provides a highly efficient computing experience, with only a marginal markup. While you can make this build totally fanless, it’s good to at least have some airflow, which in this is provided by the power supply’s very slow moving fan. The case includes a couple of fans, which you don’t really need.

The Radeon HD 7750 is among the more efficient GPUs around, although efficiency is pretty much a continuum. Picking the most efficient gaming GPU 3 Affordable AMD APU-Powered DIY Computers That You Can Build 3 Affordable AMD APU-Powered DIY Computers That You Can Build The Accelerated Processing Unit, or "APU", design integrates a graphics processing unit onto the same die as the CPU, resulting in a faster, more efficient hybrid design. For those of you seeking to build a... Read More depends on your needs.

  • CPU: Intel Core i7-4770S – $309.99 via Amazon;
  • Hard Drive: Intel 335 180 GB SSD – $129.99 via NCIX;
  • Motherboard: Gigabyte LGA 1150 Intel Z87N-WIFI mini-ITX – $134.99 via Amazon;
  • GPU: ASUS HD7770-DC-1GD5-V2 HD 7770 1 GB GDDR5 – $79.99 via Amazon;
  • Power Supply: Antec Earthwatts EA-550 550W – $99 via Amazon;
  • RAM: Patriot Viper 3 16 GB 1600 MHz (2 x 8GB) RAM – $107.99 via Amazon;
  • Heat Sink: Silverstone Tek Heligon Fanless – $64.99 via Amazon
  • Case: Silverstone PS08B microATX – $34.99 via Amazon;
  • Total: $961.93

Price accurate at time of writing.

silverstone tek

Build 2: $400-699 Midrange

For cheaper builds, Intel’s 65 watt Core i5-4630S CPU offers solid, low-wattage performance. Most of the 65 watt processors function quite well when combined with Z87 motherboards. It makes an excellent HTPC or workstation computer, with low acoustic properties and high energy efficiency.

  • CPU: Intel Core i5-4570S (65 watts) 2.9 GHz – $199 via Amazon;
  • Hard Drive: 128 GB OCZ Vertex 450 Series – $114.99 via Amazon;
  • Motherboard: Gigabyte LGA 1150 GA-Z87N-WIFI – $134.99 via Amazon;
  • RAM: Patriot Extreme Performance (2x4GB) 8 GB DDR3 1600 – $74.98 via Amazon;
  • Case + Power Supply: Realan E-K3i 120 watt – $117.98 via EcoSmartPC;
  • Total: $641.94

Price accurate at time of writing.

realan e3-ki

Build 3: Below ~$400 Low End

On lower end machines, I recommend building around AMD’s Trinity or Richland APUs. If you haven’t heard of APUs, or Accelerated Processing Units, you can read our quick primer What Is the Difference Between An APU, A CPU And A GPU? [MakeUseOf Explains] What Is the Difference Between An APU, A CPU And A GPU? [MakeUseOf Explains] Over the last five or more years, there have been a number of different terms swirling around to describe computer hardware. Some of those terms include but aren’t limited to APU, CPU, and GPU. But... Read More . It’s a combination of a CPU and a GPU in a single processor.

This particular build leverages faster RAM for better frame rate. Previously, I put together three sample APU builds 3 Affordable AMD APU-Powered DIY Computers That You Can Build 3 Affordable AMD APU-Powered DIY Computers That You Can Build The Accelerated Processing Unit, or "APU", design integrates a graphics processing unit onto the same die as the CPU, resulting in a faster, more efficient hybrid design. For those of you seeking to build a... Read More , these of course use at least 1866 MHz RAM. Depending on the motherboard, you can go up to 3000 MHz RAM with an overclock. Alternatively, you can reduce the amount of RAM or use a slightly larger case to fit the stock cooler that comes with the A6 APU.

  • APU: AMD A6-6400K (65 watt) – $64.99 via Newegg;
  • Hard Drive: Kingston V300 120 GB SSD – $59.99 via Amazon;
  • Motherboard: MSI FM2-A75MA-E35 mini-ITX – $54.99 via Amazon;
  • RAM: GeIL (2x4GB) 1866 MHz RAM – $62.99 via Amazon;
  • Case + Power Supply: Realan E-i5 120 watt – $119.99 via EcoSmartPC;
  • Cooler: Noctua NH-L9A – $42.95 via Amazon;
  • Total: $405.90

Price accurate at time of writing.


Building your own highly efficient desktop computer doesn’t take a lot of work or money — it just requires specialized parts, proper BIOS configuration and a high-efficiency power supply. For a selection of fanless, high-effciency PCs, check out FanlessTech’s entry-level, mid-range and high-level rundown of builds. Or if you’re looking for silent, fanless machines, drop by our run-down of prebuilt eco-friendly PCs Eco-Friendly Computing 101: Buy or Build Silent and Green PCs Eco-Friendly Computing 101: Buy or Build Silent and Green PCs Computer fans clog with dust, make horrible noises and waste energy. Why put up with that when consumers can go silent and green? A huge number of options popped up for setting up highly efficient... Read More .

Anyone build an eco-friendly PC? Let us know in the comments.

Image credits: Windmills via MorgueFile

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  1. Caleb
    December 15, 2015 at 4:23 pm

    I'm curious: did you ever test to see what wattage these PCs idle at? I'm currently trying to upgrade to a 24/7 desktop/server by choosing low-watt components, but I'm not sure what wattage goal is realistic.

    • Kannon Yamada
      December 15, 2015 at 5:41 pm

      With a large number of attached hard drives you might have a different idle state than my own -- but on a fanless Haswell system, with low-voltage components, by idle rate is around 12 watts. It can be much lower for a system that uses Braswell or other low power systems.

  2. Derek Snider
    June 17, 2015 at 11:51 pm

    Hi there,

    I am interested in building one of these, but the information is now a little out of date with regards to sourcing current components that are compatible.

    Would you mind making an update for 2015?

    Thanks :)

    • Kannon Yamada
      June 23, 2015 at 3:30 am

      Good idea. Braswell is probably one of the better low-end, low-power systems out there. And the Taiwanese mobo makers are now starting to release products in this range. I'm going to wait until mid summer before getting started on this one, though.

  3. southleft
    December 19, 2014 at 4:54 am

    Here in the USA we just built an HTPC based on an ASRock Q1900-ITX motherboard, a single 4GB stick of low-voltage DDR3-1333 RAM, an old Kingston 64GB SSD running Windows 8.1 Pro with Media Center, and a 2TB WD hard drive for recording TV shows. We housed it in a leftover Antec mid-tower case.

    The motherboard has an embedded Intel Celeron J1900 quad-core cpu @ 2.0GHz. Yes - an actual quad-core Celeron! But, the best part is that it's passively cooled and has a maximum power consumption of 10 watts (typically it runs at around 4 watts). So, it's silent, incredibly efficient and it records and plays 1080p video perfectly. It's also fine for internet, e-mail, casual games, light office work, etc. The WD 2TB hard drive is allowed to sleep except when recording or playing back so, overall, this system is so frugal on power that we just leave it on all the time.

    Using leftover items from previous systems such as the Antec case, a copy of Win 8.1, a stick of memory and a small capacity SSD kept our building cost to a minimum ($75 for the motherboard/cpu combo + $84 for the WD 2TB drive).

    We could have used a free version of Linux instead of Windows if necessary. In future we might splurge on one of those very small ITX cases to house the system, and that would allow us to mount it right on the back of the TV. Of course, that would require an external hard drive case resting nearby somewhere.

    • Kannon Yamada
      December 15, 2015 at 5:43 pm

      Super late response, but I ended up buying the ASRock Q1900-ITX for my own server and found it was not Linux compatible. ASRock's official line is that they don't support Linux for the Q1900-ITX, I think because they added a third party chipset to support the extra 2 SATA ports. I think with some tweaking Linux will work, but it doesn't out the box.

  4. BonesDT
    April 26, 2014 at 12:40 pm

    Since when is $425.90 below $399?

    • Kannon Y
      May 2, 2014 at 5:04 am

      Prices went up slightly. I'll correct it right away, thanks for your help!

    April 2, 2014 at 2:34 pm

    Hi Kannon, great article. I appreciate your mentioning in your builds.

    Just a couple of things. The Realan E-i5 ( makes a great substitute for the E-K3i which we haven't been carrying for a while.

    For build #3 I recommend the 120W AC adapter. You'll also need a low-profile CPU cooler since the stock AMD CPU cooler won't fit. Also, the A8-3850 is a 100W TDP CPU which I would not recommend for any of the Realan e-mini cases due to heat. The A6-6400K would be a better choice or when it is available the A8-7600 tuned to 45W and the Gigabyte A88X mini-ITX motherboard.

    If anyone has any questions on building with Realan e-mini cases, feel free to contact me (Doug) at

    Thanks again Kannon!

    • Kannon Y
      April 3, 2014 at 10:53 am

      Whoa, that was a series of pretty serious errors - it appears that somehow the wrong APU got added. It was supposed to be a Trinity quad-core or a lower end Richland dual-core, which I think was out of stock by the time this article finally published. Somehow a Llano APU got added. Hopefully no one purchased the FM1 CPU for the FM2 motherboard. I really appreciate you notifying me of the mistake!

      What's really awful about this is that I ordered the Ek3i from you (and I LOVE the case) and neglected to mention that it requires a low-profile cooler. I needed to proof-read that final entry more closely.

      I ended up pairing it with a ECS KBN-I/2100, passively-cooled motherboard and it's fantastic.

      I also have a A10-5800K(100watts) - I tested it using Kill-a-Watt and at average load (with an HD6670 in dual graphics mode) it uses around 120 watts. At max load it uses around 190watts. Would a 84-watt PSU provide enough power for a 65-watt APU, without a discrete card?

      Apologies for asking so many questions of you - but is there any reason you stopped carrying the Eik3? It's an amazing case. Most Realan cases are so well put together. It's hard understanding why they're not a bigger force in the HTPC market in the states.

  6. Shodam
    November 5, 2013 at 7:49 pm

    Since you brought HTPC use into the conversation, I'm wondering why the "little black boxes" made by folks like Western Digital (WDTV) and ASUS (Oplay) scenario wasn't brought into play. Those boxes are all fanless, stream 1080 with a mass of supported formats, are tiny and have at least some internet streaming function built in.

    All at a sub$150 US price tag.

    When paired with a networkable external drive, flash drive or even connected to a server, you have the potential for ultra small, low wattage HTPC duties at a lower cost than your budget build.

    I've put this system in place for various family members looking to duplicate a HTPC build I did several years ago. If those had existed then, I could have easily saved myself over $1000 dollars on my build, piles of energy use and simplified my space to accomplish the same tasks.

  7. Andrew R
    November 5, 2013 at 11:46 am

    I wanted a low power enviro-friendlier PC, but did not have time or experience to put it together in the time-frame I had. I opted for a mini PC ( and use it as my everyday desk top. It performs well and is much more efficient than my older PC's. I notice this particularly on how much longer the UPS lasts in a power outage. (even though I am using 2 monitors).

    • Kannon Y
      November 5, 2013 at 6:40 pm

      You chose well Andrew. That particular design uses embedded components and likely a ball-grid-array CPU connector style, meaning it's much lower wattage than a traditional desktop CPU.

      It also uses an offboard, passively cooled power supply - these are often in the high 80% of efficiencies, if not higher. While it does uses a spin up hard disk, this is mitigated by the fact it's a 2.5" drive, which means it probably uses a lot less energy than a 3.5". Very nice, thanks for sharing!

  8. shinrakurisu
    November 5, 2013 at 8:29 am

    Your timing on this article (and your link to past experiments) is impeccable, Mr. Yamada. I've spent a good deal of last week entertaining the idea of a low budget, casual/indie gaming/htpc build.

    I've been on reddit, hard forum, pc part picker, lifehacker, toms hardware, anandtech and then out of nowhere...a makeuseof article on the very things I wanted to know!


    • Kannon Y
      November 5, 2013 at 6:13 pm

      Thank you for the comment!

      May I ask what your target price is? I feel the optimal build cost for an APU is between $200 and $500. Anything more than that and one should consider an Intel build using a discrete GPU.

      If you just want an HTPC/indie gaming platform, I would target $300-350 and leave room open for expansion. Although if you want to create a highly efficient and cheap build, this limits expansion. One of the reasons I suggest the Realan series of case is that it has the efficient PicoPSU built into the frame. All the cables can reach without extension or tweaking. And it costs only about $10 to 20 more than you would pay for a lower quality case.

      Regarding quiet - APUs without proper configuration will produce quite a bit of noise. AMD's stock CPU fan isn't designed with silence in mind, unfortunately. There are compact and slow-moving CPU fans available, but these add around $40-50 to the total price of the computer. I'm using the Gemini II on my APU rig. Very quiet. But there are better fans available, such as Noctua's L9 series.

      I did a rundown of indie game bundles, by the way, that you may have some interest in checking out:

      Let me know if you need additional tips. I can write a guide.

  9. Mihir Patkar
    November 5, 2013 at 6:18 am

    Great article, Kannon! I've actually been looking to build a quiet machine for an HTPC. Any recommendations on that front?

    Will the low-end machine above get the job done for FullHD MKVs?

  10. likefunbutnot
    November 4, 2013 at 7:42 pm

    Depending on your specific needs, you might be able to get away with using either a dedicated RDP/VNC/X client device (Wyse terminals sell for peanuts on Ebay) or use a dedicated STB that happens to have available RDP/VNC client software. You're really only pushing the power use off on some other machine, but it makes a lot of sense to use a 5W client with an ARM CPU and enough horsepower to display 1080p rather than an ~80W x86 system if you just need a remote display for doing work and already have a serious desktop computer on your LAN someplace.

    Gamers are SOL on that, but gaming and power saving are generally not ever going to be a winning combination. On the other hand, a decent network connection can manage perfectly acceptable video playback over a remote desktop-type session.

    • Kannon Y
      November 5, 2013 at 4:50 am

      Awesome comment.

      I've been considering running off an ARM desktop and then using a VNC client to mirror a Windows desktop whenever I needed that sort of software. The hardware isn't quite there yet, though, unless you're talking about the Nvidia Shield. Which is a pretty fantastic device.

      I'm waiting on Qualcomm to develop a big.LITTLE chip with an optimized scheduler, though.

    • likefunbutnot
      November 5, 2013 at 5:20 pm

      @Kannon Y: The hardware is ABSOLUTELY there. Pushing 1080P video is mostly a function of having decent back-end hardware and a good network connection, but if I can interact with an RDP session as if I were sitting in front of the console on a boring old 1GHz dual core Tegra 2, it's only going to get easier.