by dan 10/05/06 12:00:00 Article hardware.

Don't throw away your old computer yet. Old computers are quite useful. I'm still using computers that are more than ten years old. I have collected 5 or so usable computers that were given to me for free and I've made sure to put them to good use. So before you decide to retire it to the dumpster, here are some suggestion for things you can do with old computers:

A file server

What is a file server? It's a computer with lots of hard disk spaces to hold files that you can share with others or you can use it to backup files from your regular-use computer. It acts as a central place to store all those files that are spread around other computers you have at home. For a home or small business file server, CPU is definitely not a factor. Really old computer can be used. I had my Pentium 150 (underclocked to 100MHz) with 64MB RAM as a file server running NASlite before relegating its duty to my other computer.

This is my main Linux server. It runs 24/7, meaning it is never turned off except for maintenance. It's a plain beige box with AMD K6-II 300MHz processor and 128MB ram. There is no monitor (ie headless) and it runs fine in a closet. It runs as a file server and a firewall/router. It's got 2 hard drives totalling 460GB of space. It's filled with photos, music, videos and stuff.
I usually run any Linux distro on it with Samba (windows file sharing). However, a dedicated file server could run NasLite or FreeNas (FreeBSD based)

What about cost of electricity?

What's so good about older computer is that they use much less electricity than most computers that are available today. Using Kill-a-watt meter, my server was consuming less than 40 watts under full load with two hard drives. That calculates to less than $6 per month. Also older CPUs are easily underclocked because CPU frequency is not locked. By lowering the clock speed, one can reduce the wattage even more. I was able to underclock (and undervolt) AMD K6-II 300MHz to 166MHz and it was down to 34 watts. However, 4 watts weren't worth the effort.

ugly and noisy?

Servers can be an eyesore so they usually get stashed inside a closet where it can stay out of sight and no one can see them. Even though there are few servers are in my bedroom closets, they are very quiet. To make them run even quieter, I could underclock them and run them without a CPU fan (ie passive cooling) being careful to keep an eye on the CPU temperature especially during summer. I prefer to use slower and quieter fan instead using the 7volt hack to quiet the fan.

Firewall and Router for company/business

Old computer makes an excellent firewall and router that can rival expensive hardware firewall/router. Running Smoothwall or m0n0wall is very easy and it can make your worthless computer into a $3000 firewall.

Media center server and MythTV

Did you know that Tivo is nothing but a computer with a tv-card and a hard drive inside? You can use your old PC like a Tivo by running MythTV. All you need is an old computer with a TV card like Hauppauge PVR-x50 for less than $70 and a hard drive to store the recorded material. With the above TV card, one can get away with a really-low end CPU since encoding is done on the TV card and CPU is not utilized that much. I have couple of old TV cards but haven't put them to use because I don't have cable TV and I can't get a good over-the-air reception via antenna. MythTV also does music so it can make a great front-end to play music in your house.

Asterisk Server

I've been playing with Asterisk recently and it is just fantastic. Asterisk is a free software that turns your computer into a powerful PBX. It can be made into a powerful answering machine with voice mails. It can be connected to VoIP provider to make cheap or free calls over the internet. The possibility is endless. It does require a FXO card/device (search Ebay for cheap) if routing calls through your regular land line. The hardware requirement is pretty low if you stick to the default codec (G.711) and don't do too much conference calls (ie partyline). People have claimed to run it on Pentium 166MHz but I haven't tried it on such a low-end system.
Many of these functions can be combined into one server instead of having multiple servers running its own thing. If the load on the server becomes too heavy, just add more servers to take up the load.

An extra computer for kids and the guests to browse the web

At home, I have a 'work' computer for serious stuff. It's my main computer and I use it to program or design. And occassionaly I have a friend or a visitor over with a request to check their emails or browse the web. This would be a perfect PC to let your guests surf the web without disturbing your main computer. I have a friend whose computer gets infected with viruses, adwares, and spywares on a regulary basis because his friends would come over to use the computer and end up clicking on bad attachments or downloading and running questionable softwares. It always ticks me off because I'm the one who has to clean up after their mess. I wanted to give him one of old spare computer.
Also if you have kids, they'll likely end up messing up the computer if left to their own devices. Having them use their own computer that you don't care about is reassuring and if something were to go wrong with the computer, you can always reinstall Windows or Linux. As for the hardware, about 5 years old or newer computers should be considered since websites now use flash animations and css heavily and they do seem to take a lot of CPU power. 800MHz and 128MB RAM should be the minimum.