Microsoft announces Azure price reductions (blogs.msdn.com)

In the comparison charts they line up their prepackaged servers with Amazon's and then compare price differences, often coming in lower than AWS. In one paragraph they make a note of this:

    Note that configuration parameters for Azure instances 
    and AWS instances are not necessarily a perfect match, 
    e.g. Azure A5 instance provides similar compute power 
    with slightly less memory (Azure 14 GB RAM vs. AWS 
    17 GB RAM).

That's a ~17.6% difference, which is not so slight.

Oh.