Laptops as routers

Nikolas Britton freebsd at
Sun Oct 31 11:23:49 PST 2004

cpghost at wrote:

>On Sat, Oct 30, 2004 at 11:38:02PM -0500, Nikolas Britton wrote:
>>Here is a better idea!
>>Step 1: Go dumpster diving for old computers (Pentium 1 or better, 8MB 
>>IDE Storage Device or better, and a minimun of 48MB/Ram).
>>Step 2: Grab some networks cards wail your in the dumpster.
>>Step 3: Install said network cards into computers.
>>Step 4: Install and configure m0n0wall on said computers. 
>>Step 5: Profit???
>>Total Cost: $0.00
>Well, depending on your geographic location, you may want to
>consider power consumption as the main cost factor here.
>A Soekris box would consume something around 5-10 Watt or so
>on average. Compare this to even the slowest Pentium. Oh, and
>they are absolutely silent as well :-)
The Soekris boxes are awesome, I'd LOVE to have one, But even with the 
power consumption, size, fanless arguments I still cannot justify the 
cost ($194 for a net4501-30 Board, Case, and PS) when I have old 
computers taking up space in my workshop. Money doesn't grow on trees in 
the world of small business.

If you are worry about power consumption or reliability when using old 
computers I have some general tips for you:
1. Don't use a storage device that has spinning disks, instead use a CF 
card, Zip Drive/Disk, etc.
2. Remove all non-essential components from the system (CD-Roms, Hard 
drives, floppy drives, add-in cards, etc) and disable in the BIOS 
anything that can't be removed (floppy controller, sound card, printer 
and serial ports, secondary IDE controller, etc.).
3. Underclock and/or mount a big heatsink onto the CPU so you can remove 
the cpu fan.
4. One 64MB stick of ram uses less power then two 32MB sticks, follow 
that logic.
5. Remove some or all case fans because, Heat Isn't an issue unless your 
cpu is like 400Mhz+, you will still have the power supply fan for cooling.

CPU (at full load): 30 Watts
Mainboard: 10 Watts
RAM: 5 Watts
3 NIC: 15 Watts
1 Fan: 5 Watts
The Unkown: 10 Watts
Total: 75 Watt Light Bulb

It will take me 3.98 years just to recoup the cost of the net4501.
(g+a)/d/c = h = 34931 (3.98 years)
a/d/c = e,   be = f,   fd = g

a = net4501-30 Board, Case, and Power Supply = $194
b = power used by net4501 = 0.012kWh
c = power used by oldcomp = 0.075kWh
d = Price (residential) of 1kWh = $0.0859
e = Number of hours I can run the computer until I spend $194 (the price 
of the net4501) in power.
f = How many kWh the net4501 will uses in the same amount of time that 
it takes me the spend $194 in power using the computer.
g = The price of those kWh's the net4501 uses
h = How long (in hours) it will take to recoup the cost of buying the 
net4501 instead of just using an old computer.

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