AWS vs On-Site Private Cloud – The Calculator

AWS vs On-Site Private Cloud – The Calculator

AWS vs On-Site Private Cloud – The Calculator

In a previous post I compared the cost of building a private virtualized development environment in house versus deploying the same infrastructure on Amazon EC2.  Given a simplistic set of assumptions about usage patterns and resource requirements, my conclusion was that building a bare-bones private cloud was about half the cost over 5 years versus building on Amazon.

In this post I’m making my Cloud Calculator Google spreadsheet available so that you can make a copy, put in your own requirements and assumptions, and see what would be the most cost effective in your environment.  I would love to get your feedback on the calculator!  Let me know whether you find it useful and if you have any suggested improvements.  Better yet, make the improvements yourself and share them back to me!

The public Google spreadsheet comes with a sample set of requirements for a more complicated – and probably more realistic – version of the previous post’s fictitious #SandTech development environment:

  • 303 total virtual servers
  • 36 physical hosts (in private cloud)
  • 5 TB of network storage
  • Server instance memory requirements ranging from 600MB to 68GB
  • 60% of the servers in use around 50 hours per week
  • 30% of the servers in use around 16 hours per week
  • 4 database servers in use 100%
  • A dozen Map/Reduce nodes running around 67 hours per week

Below is an image of the spreadsheet’s Summary tab, showing the 3 and 5 year costs for each option.  In this case, Amazon AWS wins the cost contest over a 3 year period, though it still loses out over 5 years.  The calculator also shows the possible savings of a hybrid solution where the highly utilized nodes reside in the private cloud and the “burst” nodes sit on Amazon.

Give it a go and let me know what you think!

Cloud Calculator