Tag Archives: energy

Switching to an energy-efficient desktop computer

Since 1990, I’ve had IBM-compatible desktop computers in my life. Before that, I had Tandy computers beginning at age 2. At first, they were the only computers I had, so I did everything with them – gaming, BBS surfing and eventually the internet, word processing, etc. In college, I got really into video encoding and I played all the newest games, which required quite a bit of PC hardware. Since then, I’ve done less and less encoding and gaming, and have settled into a state where all I do with my desktop machine is surf the web and watch HD movies and TV shows.

Now, decoding HD video isn’t exactly the easiest task ever. Routinely, playing 1080p video would peg one of my processor cores at 100%, and I felt that justified keeping the extra horsepower around. About a year ago, I started experimenting with VDPAU, which allows UNIX machines to offload video decoding tasks to the GPU. I bought a new video card basically just to mess around with this feature, and eventually I got it working very well. I’ve been using it for all my video decoding needs. Recently, I found out that YouTube and a couple other sites started supporting hardware video acceleration in their Flash movie players. Since I do actually watch a lot of video online, this was pretty much the last thing keeping me away from low-power CPUs. I found out about the Nvidia ION chipset, which supports VDPAU, and happens to come on a lot of Mini-ITX motherboards. Now, if I could find the right combination of hardware, it would finally make sense to try and trim down my desktop.

My system was a X3220 Xeon Quad core processor. I had 4GB of RAM, but I never touched most of it. I had 3 2TB hard disks in a RAID5, and a 120GB Raptor root drive. I also had a Blu-Ray burner, which brings us to a total of 5 SATA devices. I ended up buying a ZOTAC IONITX-A-U Atom 330 1.6GHz Dual-Core 441 NVIDIA ION Mini ITX Motherboard/CPU Combo for $179, one day before they lowered the price and the rebate came out, which makes it $155 today (lucky you if you choose to follow in my footsteps). It has 3 SATA connections, and 1 eSATA on the back, and about a million USB ports. I’m going to hook up one of my RAID HDs with the eSATA, all the other HDs with the regular SATA, and I bought a $10 converter for the Blu-Ray drive from SATA to USB.

This is where the fun begins. The day I received the board, I quickly stripped the RAM out of my desktop and put it into the little Zotac. Once I got everything hooked up (at this point, just the Blu-Ray and my root disk, along with my TV and monitor). I booted it, and it performed beautifully. There were exactly zero snags getting it to boot into Ubuntu. Once in, I got to work making everything work correctly with the Nvidia ION and VDPAU and Flash. I managed to get it all working with the Nvidia 260.19.06 driver and Flash 10.2 d151 32-bit. This is a bit of a complicated process, and will be much easier once Adobe makes 64-bit Flash support VDPAU. This is only available in the 32-bit beta at the moment, and all this went down around November 2010.

The process for getting all this working is just barely documented here and here. You basically have to install getlibs to download and install a 32-bit version of libvdpau, then download npwrapper, which wraps 32-bit plugins with 64-bit bindings to make it work in all your favorite 64-bit browsers. Yeah, it sucks, but hopefully you’ll only have to do it once.

I can play Big Buck Bunny in 1080p completely smoothly (as long as my connection can keep up) with only about 30% CPU usage! I can also play pretty much everything in mplayer with VDPAU smoothly. But how has my power consumption been affected?

Before the changeover, I measured my computer’s consumption with a Kill-a-watt meter for several days. Idling with everything else off, the computer consumed around 160W. My old processor’s max TDP was 105W, and the idle wasn’t pretty either. The new Atom 330‘s max TDP is only 8W! Just changing this one component brought my current idle power consumption down to about 60W according to the meter, a 100W savings. Since power costs around 10 cents per KWh, and my old computer was using 3.84KWh/day, it cost around $12/month to keep it on all the time. Now, it’s only about $4.50/month. Obviously, this isn’t a HUGE savings, but considering I don’t have a giant loud computer next to me taking up space for no reason, I think it’s kinda neat. Also, this brings my computer well within the realm of being able to run exclusively on solar power, once I get my panels and inverter installed.

Since I bought a Mini-ITX motherboard, I could complete one of the projects I’ve had in mind for about 3 years now – an old-school toaster machine. I’ve had this toaster body for several years, and I really like it. I cut out the back panel with a plasma torch – that thing cuts this sheet metal like butter. Mounting the board inside was difficult – I tried welding the standoffs to the frame, only to realize they were aluminum and promptly melted when exposed to my steel weld wire. Kelsey and I pondered for a bit, and came up with hot glue as a solution. We went to Michael’s (eww), and got supplies. I hot glued all the standoffs to the inside of the toaster and let it set up for 10 minutes or so. This worked very nicely. After checking about 5 times to make sure nothing was shorted, I hooked up everything, and hit the power pins with a screwdriver blade. It powered up! I’m typing on the system right now, and it’s purring quietly. I can feel the very slightest bit of heat coming out of the top. I’ll post pictures as soon as I figure out how I can hook up my USB card reader.


Is it time for the Electric Car?

A reader asked about the Chevy Volt in comparison to the Honda Civic, which is a wonderful question. The Volt people claim that it can go 40 miles on just batteries, which is perfect for most people’s commutes provided they can plug in at work (or not for the really lucky ones). So, it’s obvious that there is no fuel consumed by the vehicle in these first few miles of driving, but I’m going to look at how much fuel is consumed to create those 8.8 kilowatts of electricity it takes to go 40 miles. First, the 8.8 number comes from Chevy’s claim that the gas engine kicks in at 30% battery charge, and the battery will only charge to 85% from the wall outlet, meaning it goes 40 miles on 55% of the battery capacity (16 KW), which equals 8.8 KW.
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Buying a fuel-efficient used car versus a new Prius

Update: I just found this article, which has the same point as mine, and assumes domestic production. It also pre-dates mine – that will teach me not to use google!

As one who drives a 2000 Honda Civic, which in many real-world driving tests gets almost exactly 30 MPG consistently (I keep pump logs), I wonder if I would actually create a net reduction in gas consumption by buying a Prius or other car. Now, I’m assuming a new Prius, but buying a used one is perfectly valid, and is outside the scope of this article. If you want to do that, more power to you – that’s a good choice hands down. Yet, most people I know would opt for a new one. Based on various seemingly valid estimates, it takes 113,322,000 BTUs to create and import a brand new Prius. It takes 0 BTUs to park a used Honda Civic on a lot until someone buys it.

So, for the data used to obtain this, I looked all over for real road tests of the Prius fuel economy.  This one seemed to fit well with everything else I’d been reading, giving an average range of 42.6-45.2 MPG.  So, I’m going to say 43 MPG.

The Prius uses enough gas to create 2639.53 BTUs per mile.  The Civic: 3783.33.  At these rates, and coupled with the initial component of the BTUs used to manufacture and import the Prius, we come up with the following:

$latex 2639.53x + 113322000 = 3783.33x$

$latex x = 99075.01$

Graphing this in gnuplot, we get the following:

plotSo, one would have to drive almost 100,000 miles to get an advantage over simply buying a used Civic.  Interesting.  Here’s the GNUPlot Plot File for anyone that’s interested.