I use 'htop' to monitor my web server. It's recently quite loaded and the Load average is showing something like this:

Load average: 3.10 2.56 1.63

I searched the web about these numbers and I found an article about it: http://blog.scoutapp.com/articles/2009/07/31/understanding-load-averages

In the article, it says if I have 2 CPUs, 2.0 means 100% CPU utilization.

And my VPS has two CPUs, so what does 3.1 mean? How could it exceed 100% CPU utilization?

And from these numbers, does it mean I should be wary about the loading now? But the performance seems totally fine, and this is a managed VPS, the hosting company has not notified me any warning about it.

During day time, Load average always show these high numbers... here is another snapshot while writing.

Load average: 3.03 2.77 1.97
Load average: 0.41 1.29 1.60 <---- 5 more minutes later

So I am wondering how much room left for this site to grow in current configurations? What kind of proactive actions I should take in advance?

I don't want to wait until the server bursts.

Thanks.