Amazon can. That has no information about how the nodes were allocated. They could have hand picked X rack of nodes that were all connected via the same switch, etc. You don't get that guarantee from AWS.
Fair enough, I guess.... they could have done many things.
Although they do not provide an answer, here are some links to additional info - I spent some time searching for additional info on the Top500 setup, but found little:
Although they do not provide an answer, here are some links to additional info - I spent some time searching for additional info on the Top500 setup, but found little:
* http://aws.typepad.com/aws/2010/07/the-new-amazon-ec2-instan... * http://news.ycombinator.com/item?id=1904590