How to build an energy efficient gaming PC

Are you a gamer with a big electricity bill every month? Are you looking to build a great gaming PC that doesn’t sound like a jet engine every time you start playing Diablo III? This build guide is for you.

Imagine a PC that will hit 60 frames per second running most games on today’s 1080p displays. Now imagine that system idling at under 70 watts. Even under the heaviest load, it consumes just 336 watts. That’s 336 watts generated when the system is running an eight-core instance of Prime 95 while simultaneously running 3DMark 2011 at 2560 by 1600 resolution with 8x antialiasing on–a far heavier load than most games will produce.

Better yet, this system makes few compromises in terms of overall performance. It runs the latest LGA 2011 hardware, including a quad-core Sandy Bridge Extreme CPU. It has 16GB of RAM, too, and a powerful current-generation graphics card.

Let’s go on a tour of the system first. Afterward I’ll dig into the component choices to show you how I built a killer system that’s fairly green. Click on any picture to zoom in for full details, and then click the left and right arrows to look through the photos.


It isn’t much to look at, certainly, but that’s part of its charm. The case is a Corsair Obsidian 550D midsize-tower chassis. Offering most of the amenities of high-end cases, it’s also designed to minimize noise. The front cover hides the optical drive, but its real purpose is to help baffle noise.


This gaming machine isn’t just easy on your electric bill, it’s also remarkably quiet thanks to some simple soundproofing. Though you can’t see it in these pictures, the dense foam material lining the front cover also lines the two side panels.


With the PC’s front cover removed, you can see the optical drive nestled near the top of the tower. These days I download most of my games, but I threw in a Blu-ray combo drive–a Blu-ray reader plus a DVD burner–for the odd DVD-based game as well as the occasional high-definition movie. The Corsair case is also a nice choice because it fully supports internal USB 3.0 connections for the front-panel USB ports. The power and reset buttons remain exposed even when the cover is installed.

Like most current-generation systems, this machine has plenty of input/output options, including lots of USB 3.0 ports, eSATA support, two flavours of digital audio outputs, gigabit ethernet, and multichannel analog audio. It even sports a PS/2 keyboard connector for hard-core gamers who want to use PS/2 keyboards capable of supporting overloaded keystrokes.


Like most of Corsair’s cases, the 550D has plenty of room under the motherboard tray to route power and other cables.

System performance

Now that you’ve had a brief tour of the system, it’s time to talk performance. Although this machine is built to run PC games at high frame rates, it’s also not a bad all-around performer, and it posted great results in our PCMark 7 and 3DMark testing regimen. Both benchmarking utilities offer simplified versions that are free to download, so grab a copy of each and run your own tests to see how your PC stacks up against our power-sipping gaming machine.
For reference, we ran all the games at 1920 by 1200 resolution, with all detail levels completely maxed out and 4x multisampling antialiasing enabled. The Mainconcept test transcoded a 4.3GB high-definition video file from 1080p MPEG-2 to H.264 iPhone (304MB final size).

These performance numbers are quite good, coming within a few per centage points of a system running a Core i7-3960X CPU. Yet our PC idles at just 69W, significantly lower than the power usage of most gaming PCs (which pull hundreds of watts out of your outlet). What’s inside this box? Let’s take a look.


It’s all about power

The key to the power efficiency of this system was selecting the right power supply. One important aspect of the decision was my complete lack of desire for a second GPU. Instead, I wanted a single, high-performance graphics card that could handle almost anything I threw at it.

Freeing myself from the need for a second GPU allowed me to pick a power supply with just two PCI Express graphics connectors. That power supply is the Antec Earthwatts Platinum 650W unit, which is 80 Plus Platinum certified. A power supply that’s 80 Plus Platinum certified must maintain close to 90 per cent efficiency throughout its range, even under load and idle extremes.


The upside is low maximum power consumption and high efficiency. The downside is that we have only two PCI Express power connectors and a lack of modularity–all existing power connectors are permanently attached. If you need more power for a second GPU, a great alternative is Seasonic’s Platinum 860W power supply, but that would set you back $220 instead of the Antec’s $120 cost.

Nvidia finally gets power efficiency

Maybe it’s all the effort Nvidia has been spending lately on building low-power processors for mobile devices. Or maybe the company just got tired of having low-wattage sand kicked in its face by AMD. Whatever the reason, Nvidia’s latest high-end GPU, the GeForce GTX 680, is a power-sipping prodigy. The Asus-branded GTX 680 card I selected requires two six-pin power connectors, something unheard of in a flagship graphics card.

Nvidia also endowed the GTX 680 with the ability to support four displays; I currently have one running three 30-inch panels on my desktop, which gives me a total of 12 megapixels of screen real estate. Trust me, that’s a lot of windows.

The GTX 680 is certainly faster than AMD’s flagship Radeon HD 7970, but it’s also smaller, quieter, and cooler. The 1536 GPU cores translate into superb performance in modern PC games. Even a huge performance hog such as Metro 2033 reaches over 30 frames per second at 1920 by 1200 screen resolution. Perhaps more representative is the 62 fps we saw in Batman: Arkham City at 1920 by 1200, with maximum detail levels and 4x multisampling antialiasing enabled.

The processor-motherboard-memory triangle

I wanted a platform that offered growth potential without sacrificing performance. That meant LGA 2011, which supports huge memory bandwidth and Intel’s top-of-the-line CPUs. On the other hand, I didn’t want to break the bank, so I opted for the lowest-cost LGA 2011 CPU: the quad-core Core i7-3820. It has 10MB of L3 cache, a quad-channel DDR3 memory controller, and Hyper-Threading support. It includes a staggering 40 PCI Express lanes, making it suitable for multi-GPU setups, if you so desire. Offering a base clock of 3.6GHz and a maximum Turbo Boost speed of 3.8GHz, it’s no performance slouch. The two additional cores that ship with the pricier 3920K and 3960X CPUs won’t add much to gaming performance, either.

The underlying motherboard platform is the Gigabyte GA-X79-UD3 board, based on Intel’s X79 chipset. It’s one of the more power-efficient X79 boards available.


A good motherboard and CPU demand good memory, but I also wanted efficient memory. Kingston supplied us with a pair of 8GB HyperX LoVo memory kits. They’re capable of running at 1600MHz while sipping just 1.5V (instead of the usual 1.65V), but I kept them at the default 1333MHz. After all, with four memory channels available, there’s no lack of memory bandwidth.


I used Corsair’s H60 sealed liquid CPU cooling system, which you can see in the open-case photo above. A sealed liquid cooler offers a lower profile than big air coolers do, so it improves overall airflow while maintaining a sub-40 degrees Celsius idle CPU temperature.


Want fast storage or lots of storage? How about both? The boot drive on this system is a 250GB Intel 510 Series solid-state drive.


The secondary drive is a two-platter, WD1002 FAEX hard drive, which offers enough storage for user data folders.


Note that the optical drive I used in this ultra-quiet and energy-efficient gaming PC is Asus’s latest Blu-ray combo drive, the BC-12B1ST. At under $60, it’s not much pricier than standard DVD drives.

For the operating system, I’m using Windows 7 Ultimate (64-bit), but Windows 7 Professional would do just as well. These days I avoid Windows 7 Home Premium due to its 16GB memory limit.

Cost and alternatives

This system is efficient and relatively quiet, and it offers good potential for future expansion–but it is a high-end system. Let’s see how it prices out.

In the end, what we have is a high-end gaming rig with lots of RAM, a superb graphics card, an SSD boot drive, and plenty of secondary storage. If I wanted a lower-cost system, I might go with one of the new Ivy Bridge CPUs, although I’d have to wait a few weeks until they became more widely available. The Core i7-3770K will likely cost a few dollars more, but a motherboard based on the Z77 chipset will cost less than an X79 motherboard.

If you’re using Ivy Bridge, you could buy just 8GB of RAM, which would cut memory costs in half. I’d keep the 1TB Western Digital hard drive, but replace the Intel 510 with a much smaller, lower-cost SSD that could act as a very fast hard-drive cache using Intel’s SmartResponse technology. Storage costs would probably be more like $270 instead of $660. The total cost of the hypothetical Ivy Bridge system would drop down below the $2K mark.

One other possible change: Graphics cards based on Nvidia’s GTX 680 GPU are in short supply currently, but you can easily find an AMD Radeon HD 7970 for about $480. It’s nearly as fast and just a tad noisier, and it consumes only a little more power.

Still, I’d be loath to give up this nifty LGA 2011 system. LGA 2011 will live beyond the current Sandy Bridge Extreme and support a future Ivy Bridge-based CPU, so it still has some growth potential. And even if LGA 2011 never sees an upgrade, it should handle today’s PC games and future titles with aplomb. Build it into a system such as the one shown here, and you can play games at any hour of the day or night without waking relatives or roommates, or racking up a huge electricity bill. Good luck!

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Jim Love, Chief Content Officer, IT World Canada

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