On another note - these kinds of "let's go back and check what we can do with a single node today" approaches are valuable to recalibrate our thinking once in a while. I didn't interpret this post as a case against distributed processing - there are many things going for it - but just to avoid falling into hype.

A couple of great posts by Frank McSherry along the same lines a few years ago, doing page rank for a 128bil edge graph on a single laptop (in the second post below) -

The first post - "scalability! But at what cost" http://www.frankmcsherry.org/graph/scalability/cost/2015/01/...

The second post - "bigger data, same laptop" http://www.frankmcsherry.org/graph/scalability/cost/2015/02/...