Quote from the page above
Light and Medium Utilization Reserved Instances also are billed by the instance-hour for the time that instances are in a running state; if you do not run the instance in an hour, there is zero usage charge. Partial instance-hours consumed are billed as full hours. Heavy Utilization Reserved Instances are billed for every hour during the entire Reserved Instance term (which means you’re charged the hourly fee regardless of whether any usage has occurred during an hour). "
I think you pasted the wrong link, though. Here's the page which contains that quote: http://aws.amazon.com/ec2/pricing/#reserved
havent done a check to see if he was taking into account the discounted hourly price or just adding on on-demand hours...
It would also be nice to have values on the x axis of the graph so I can see exactly when certain thresholds are crossed - as of right now I'm just assuming that the max x-value is my specified days * 24.
Again, cool idea, but I'd be more inclined to hit up the AWS Cost Calculator (http://calculator.s3.amazonaws.com/calc5.html). It's ugly, but it allows me to quickly add many resources from all of the AWS services for a total monthly cost.
X axis value seems to be some browser issue. On some browsers it shows up only at reduced zooms. Will fix it.
Also, we are not trying to replace AWS cost calculator. It was more like putting our own dog food out to answer the question, that at what point/usage is the reserved instance better than on demand.
Edit : changes pushed.
Feedback: The top bar folds over when the browser window is resized (looks like anything less than 1024 px). The page then starts to overlap on itself blocking out content at the top.
How did you code up the graphing part? HTML5?
EDIT: fixed autocorrect