Today, I was talking with one of our developers about the barriers to starting your own social network (Ning, not withstanding). After a little back and forth, he said that, of all the barriers, pure energy costs of running and maintaining servers would be the toughest to crack. My response was that we could probably just hire a bunch of people to ride bicycles and power the servers at a much cheaper cost. Almost inevitably, this led us to wonder how many bicycles it would take to power Facebook’s servers. I sat down with our SysAdmin and did a little rough math to figure it out:
First of all, we needed to know how many watts single person can generate on a bicycle. A quick Google search led us to believe that the average adult can generate between 75 and 400 watts. For the sake of simplicity, we used an average value of around 200 watts per person.
Next up: Watts per server. Luckily, we could just use the value from our own servers: approximately 400 watts. This means you’d need 2 bicycles for every server.
We guesstimated that Facebook has approximately 40,000 servers (someone feel free to give me the real number). At 2 bikes per server, you’d have to station 80,000 bicycles in your server facility. That’s a lot of bikes!
But then there are the people. Assuming 8-hours of activity per shift (broken up so that each person could have rests, Facebook aren’t slave drivers, after all), and the constant need for energy, you’d need 240,000 people to power Facebook 24 hours a day, 7 days a week. This number goes up even more if you allow for more breaks/shorter shifts/weekends off/vacation time/etc.
Next time you think your job sucks, think about how you could be doing this instead:
Original photo by xtracycle
