Every web startup dreams of amassing millions of users and seeing the kind of growth Facebook or Twitter have. But all this growth may be a curse as much as a blessing if your infrastructure can’t keep up. Looking at Twitter’s recent troubles, it’s an easy point to prove. Facebook, on the other hand, doesn’t seem to be having any growing pains and that may be in part due to a massive rise in the number of servers it uses to handle close to 500 million users.

A report on DataCenterKnowledge, estimates the number of servers currently under Facebook’s command at about 60,000, double what it had a little over six months ago. Facebook doesn’t disclose any numbers itself, though it did at one point, but it has provided a chart showing the rise in the servers it employs.

The chart shows a sharp increase in server count in recent months and a steady rise over all of 2009 and most of 2008. Facebook has had a constant need to add more servers to keep up with demand from its increasing number of users. Facebook is now several times larger than it was just a year ago and its users spend more time on the site as well.

The rise in usage of its video feature and the popularity of its photos section put even more pressure on the infrastructure. Of course, handling just the basic interactions of 500 million people, 200 million of which visit every day, is a daunting task in itself.

So Facebook’s need for more computing power is understandable, but where do the numbers come from? Well, Facebook revealed last fall, in November, that it had more than 30,000 servers. It was an impressive figure at the time, but looking at the chart, it’s clear that Facebook was just getting started. Based on that figure and the fact that the chart shows that the social network has about double the number of servers it had in November, the 60,000 servers figure is easy to arrive at.