Can someone explain the concept of an “instance-hour” as used by cloud computing providers?

Question

I am looking at the pricing of various cloud computing platforms, particularly Amazon's EC2, and a lot of the quotes are based on a unit called an Instance-Hour.

I am trying to get a handle on the exact definition of an instance-hour to better compare the costs of continuing to host a web-application versus putting it out on the cloud.

(1) Does it correspond to any of the Windows performance counters in such a way that I could benchmark our current implementation and use it in their pricing calculators?

(2) How does a multi-processor instance figure into the instance-hour calculation?

Answer 1

Instance hour is your regular hour where the instance was available for you to use, whether you used it or not. For Amazon resources, you pay for the type of resource you are getting and not for how much you use it.

So, the answer to your first question is, it's just a regular hour. And the answer to your second question is, the multi-processor instance is already factored into the price you pay for the instance per hour.