I don't know that it would be difficult to reproduce the test that is mentioned in the paper linked below, but they do mention the following anyways for EC2: >

I don't know that it would be difficult to reproduce the test that is mentioned in the paper linked below, but they do mention the following anyways for EC2: > A single account was never seen to have two instances simultaneously running on the same physical machine, so running n instances in parallel under a single account results in placement on n separate machines