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Building an Energy Efficient, Always-On PC?
An anonymous reader asks: "Like many readers, I find it necessary to leave my home PC running 24/7, for things like web or FTP servers, BitTorrent, or simply to make sure I don't miss any messages on IRC or my instant messaging client. It has been about 3 years since I built my current PC, and keeping it running all the time uses a lot of juice. With my next PC, I would like to do what I can to keep the power-consumption to a minimum, without sacrificing processing power or other features. What should I look for when choosing components for my PC, and what other ways are there to keep the power consumption down?"
Using an LCD monitor instead of a CRT will drastically cut your power usage. Turning off the monitor while not at your computer will help as well, instead of just letting the screensaver run. The monitor can consume more power than the PC itself.
I just recently bought a Kuro Box for exactly the same reasons - low power, low noise, always on. You can load it up with Gentoo or Debian, so you can do bittorrent, ftp, http, etc. And it's cheap!
The only downside is that it's headless, but for me that wasn't an issue. If that really bugs you, you can set up a vnc server on it and graphically steer it from your PC.
Check out the kuro website. It has links to their wiki and forum.
A laptop is already constructed to use as little power as possible, so for non-performance critical tasks, it would probably be quite useful for an always-on server. Built-in UPS is also handy, and it can be tucked away in some closet without taking any room, while still having an emergency keyboard and screen if you need to perform administration tasks on it.
For storage, a couple of USB-drives would be useful, I bet they don't draw much more power than the drive itself.
c++;
Check out your underclocking options on your current machine; I found that Linux's 'ondemand' cpufreq policy governor made a real difference on my machine: http://parseerror.com/~pizza/cpufreq.html You can also check around in your BIOS to underclock your machine; but the disadvantage there is that the change is permanent; with Linux's CPU governors and a modern CPU your machine runs at full clockspeed only when the cycles are needed; I believe Windows has similar options.
Buy yourself a used Pentium-M based laptop. If you don't need to actually use the computer directly, buy one with the screen broken, which tends to make for some darned cheap laptops. You can hook up a monitor to it, which is how you'll put your OS on it. (Remember, laptops have mouse ports, USB ports, and display, so you can use them as a conventional computer just fine, and most laptops have the graphics chips to drive a higher resolution that their native LCD resolution.) The money you save on buying a cheap laptop like that make up for a lot of power bill, especially with the broken screen bonus.
Get the model number of the laptop in advance, cross-reference that with the chip that it uses, then find the power consumption for that chip if you want to double check. I hear the later-model ones are (surprise surprise) more efficient, but they're all pretty good AFAIK.
As somebody else said, the built-in UPC isn't bad, and a Pentium M will have all the power you need for non-floating-point functions; any Pentium M can handle even a moderately-sized website if you wanted.
A good option is to get a cheap virtual host. You get root, install what you like, run what you like, and it uses less power - none of yours - because there are several mostly-idle virtual machines on the same host.
Disk space is relatively expensive, and this may not be an option for you if by 'BitTorrent' you mean 'fill up my 500GB hard drive'.
A C7 would likely be a much better choice for a webserver, you get SATA, and a much faster processor, which is much more suited to serving web traffic. And if you're hosting torrent files you will likely be having lots of disk access, making SATA a huge benefit.
Sorry dude, Core 2s do NOT have significantly lower power consumption than AMD processors.
And even when they do, it is not so spectacular when you factor in the lack of a memory controller. (I like the Core 2, hate the P4)
Sorry, this is a COMPLEX subject. How so? Intel and AMD measure Power needs by a different yardstick. AMD makes many parts, has two different processes, and even on the same process has varying power needs.
The AMD 65nm desktop chips use VERY LITTLE power, often kicking the butt of the core 2 duo, especially at idle.
If you really want to save power on a powerfull x86, you undervolt/underclock a 3600x2 65nm chip. At this point, you will worry much more about the power consumption of your Power Supply, Video Chipset and Hard Drive.
As some have suggested, Plug in a large Flash memory device for files accessed but not updated regularly, spin down the HD after a time delay(HD's have a finite number of start ups), look for an efficient supply, and look at the newer AMD integrated video chipsets.(I think you will find these chips consume much less current than others)