Perhaps this is a historical question, but I was wondering how the default OpenStack flavor size ratio of 2/1 was determined? According to http://aws.amazon.com/ec2/instance-types/, ec2 defines the flavors for General Purpose (M3) at about 3.7/1, with Compute Intensive (C3) at about 1.9/1 and Memory Intensive (R3) at about 7.6/1. -David