Despite misconceptions about green computing, a do-it-yourself solution can offer both cheaper build and power costs than conventional alternatives. Some erroneously claim that the power saved won’t amount to the cost of the build, but the math shows rather large savings over the lifespan of a computer, especially for Europeans. In my experiment, I built a 15-watt desktop computer, which provides decent performance as a media center, web browser and light gaming machine.
Assuming the computer operates for eight hours a day with electricity costing $0.15 per kilowatt/hour (kWh), the cost of powering it comes out to $6.57 a year. My green machine cost only $250 to build. A beefier machine, such as a $500 Gateway DX4870-UR3D desktop, for example, consumes around 70 watts, costing $30.66 per year. Over a four-year upgrade cycle, you would save $96.36 in power costs by using a greener machine, in addition to $250 in components. For many European and Asian countries, this number increases dramatically.
On the downside, less watts means less raw processing power – but if you don’t require a heavy duty computer, and tablets don’t do it for you, a greener PC build might be exactly what you need.
This article covers some of the build decisions that I made. I also cover the power costs of an eco-friendly computer, compared to a standard 70-watt desktop.
Building an Eco-Friendly PC
Throwing together an efficient, eco-friendly PC requires both software and hardware optimizations. I elected to go entirely fanless, which saves a substantial amount of power during periods of operation. Fans typically require around 3-5 watts each. The ATX (desktop) specification calls for 3 fans, meaning a drain of 9-15 watts. I also elected to use a highly efficient power supply, which converts from wall current at over 96% efficiency, 70% being standard. Building a highly efficient computer isn’t very difficult, either.
I selected AMD’s Accelerated Processing Unit (APU) technology, which functions best with relatively large amounts of high-speed RAM (1866 MHz preferred, for cost reasons), offering efficient, although meek, graphics in price-performance ratios.
The two best mini-ITX motherboards are Intel’s Bay Trail or AMD’s Kabini lines. To my knowledge, as of 2013, only ECS manufactures motherboards for either technology.
I use power prices throughout North America, Asia and Europe as a means of demonstrating how much money can be saved using power-sipping, eco-friendly builds. I also explain how little money it takes to build lighter desktop computer.
After some deliberation, I elected to orient the new build toward power efficiency and low-cost. Because I had already purchased a mini-ITX case, following a bungled experiment at building a powerful and efficient desktop, I already owned a case and power supply. My new build would aim toward functioning as a media center and light gaming rig, instead of a coding-rig.
Using a variety of money-saving methods involving IFTTT and Yahoo Pipes, I managed to complete construction for under $250. Without using any special means, you can build the same system for around $350.
- Power supply + case: The best combination package is the Realan E3-Ki from EcoSmartPC. It includes a high efficiency power supply and a slick, high-quality case for about $85, although it is currently sold out. The Realan case combines a picoPSU with a mini-ITX case, which you can find in a combo deal on eBay.
- RAM: You won’t require much RAM to run an eco-friendly PC. About 4-8 gigabytes is more than enough.
- Motherboard + CPU: I used an ECS KBN-I/2100 ($41 after rebate), but Intel’s Bay Trail based motherboards provide similar power savings, with a slightly different feature suite. The AMD APU-based builds (what is an APU?) provide superior media and gaming functionality, whereas the “Atom” Intel based motherboards possess greater general functionality. The advantage of the KBN-I/2100 is that it includes Linux support out-the-door. I’ve also found that APUs offer great performance per dollar.
- SSD: You will definitely want to use an SSD for both its small size and lower wattage requirements. Just make sure you properly install and configure your SSD. Some software tools can help you with the SSD configuration and optimization process.
- Total: Less than $250 (my costs) or around $350 if you pay full retail.
Using Kill-a-Watt (and the power consumption measurement method outlined by Matt), the standard power consumption of my computer cost 15 watts. I’m assuming my power costs are around $0.15 per kilowatt/hour, although in some countries/regions, prices can reach astronomical sums, such as Germany ($0.35/kwh) or Denmark ($0.41/kwh).
- Idle: 13 watts
- Sleep: 1.9 watts
- Maximum load: 20.2 watts
- Prime95 stress test: 18.2 watts
- Operational power consumption: 15 watts
- Yearly power cost: $6.57
Overall, my power costs on a custom build, including the 19-inch monitor, came in below the power requirements of even a 35-watt laptop. This may appear counter-intuitive at first, but given that my desktop uses a low power solid state drive and dispenses with cooling fans, the power savings aren’t without explanation.
International Power Costs
According to compiled statistics, energy prices in Denmark come in at $0.41 per kWh, making it the most expensive country in the world to use electronics, or anything powered by electricity. Over a four-year upgrade cycle, a 15-watt computer would save $263.36 over a 70-watt computer. Even in countries with the lowest power costs — India and Russia — an individual would save $51.40 over a four-year period.
I tested my new computer out in a variety of ways – as a Litecoin miner, media center, light gaming machine and as a Linux box. In three of these four categories, it does quite well.
As a cryptocoin miner, I found that my new system provided a relatively mediocre hashrate per watt – 13 khash/s on the Scrypt hash function (my experiments with alternative cryptocoins). However, its wattage consumption at maximum GPU load was only 20.2 watts. 20.2 watts costs a pittance, compared to what a beefier machine could consume.
Overall, it’s not particularly effective as a mining rig.
Light Gaming Machine
It also played a number of games without much difficulty, most notably the excellent Wolf Among Us by Telltale Games. It actually plays on the maximum settings in high definition, something of a shock to me, despite the game’s relatively anemic requirements.
For running Humble Indie Bundles (check out my list of indie game bundles), weaker computer can offer decent performance. Indie games in general don’t require beefier processors or GPUs, so the integrated GPU inside of my motherboard offered good enough performance.
The green PC could also stream and process high definition video, which is something of a feat on a budget, low-wattage platform.
The ECS KBN-I/2100 motherboard that I used is supported by Linux, out-the-door.
If tablets aren’t your thing, you can build your own eco-friendly system that will save you money. It won’t perform computationally demanding activities, but it will provide better than tablet performance for running many mundane tasks, such as web-browsing, light gaming or media streaming.
In countries with high energy costs, it will save you hundreds a year over desktops and provides slightly better power efficiency than many laptops.
Anyone else save money with an eco-friendly computer? Let us know in the comments.
Image Credits: Stack of coins via MorgueFile