Windows Azure Storage vs Local Storage

If I do sessions on Windows Azure, I always point out that we as software engineers/architects should think about costs again. Because Windows Azure may look more expensive in comparison of an on premise situation, but we as developers have influence on it.

Ok, the different VM’s of course have standard costs. And as I told in my previous blogpost, when you combine roles this could help you. Hereby a list of the standard costs of a VM per month. Please notice the table goes for 1 instance of a VM. Look here for the calculation with more instances.

      Cost per Month
VM Storage per hour  
Extra Large 2040 0.96 700.80
Large 1000 0.48 350.40
Medium 490 0.24 175.20
Small 225 0.12 87.60
Extra Small 20 0.05 36.50

The combination of roles can get some advances, but efficient programming also can save some money. For example (code example taken from Maarten Balliauw).


Unnecessary to explain with this saves some CPU clock cycles and save some money.

Other cost saving can be gotten by efficient use of local storage. The storage in a VM is foremost meant for your application of website resources. Of course you can use it for pictures etc. for your website, but realize two things. First this storage can not be use with CDN. With this your users always have to go the full distance to get the picture, also when a Windows Azure datacenter not in the neighborhood. Second the local disk is expensive.

In the table below I have put the costs of the VM plus their storage. The storage costs are calculated by dividing the amount per month by the available storage..

      Cost per Month Storage Costs
VM Storage per hour GB/Month
Extra Large 2040 0.96 700.80 0.34
Large 1000 0.48 350.40 0.35
Medium 490 0.24 175.20 0.36
Small 225 0.12 87.60 0.39
Extra Small 20 0.05 36.50 1.83

For critical people who will say the VM price does not apply to the complete storage but also for CPU/Memory/Network. That is true, image the it is halve the price. Even then the local storage is still expensive.

      Cost per Month Storage Costs
VM Storage per hour GB/Month
Extra Large 2040 0.96 350.40 0.17
Large 1000 0.48 175.20 0.18
Medium 490 0.24 87.60 0.18
Small 225 0.12 43.80 0.19
Extra Small 20 0.05 18.25 0.91

And keep in mind you need a minimum of two instances. With that the local storage also doubles and so do the costs.

Of course my calculation can be subject of discussion, no problem. The point I did want to make with this blog post is, that we developers and architects have influence and are responsible of the costs of a Windows Azure application.

But put your remarks in the remarks. Thanks!

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