In a world of multiple CPU cores, clusters, and grids, how do we define supercomputing?

Is supercomputing simply more boxes performing ‘embarrassingly parallel’ jobs or does it require massive single system images (SSI) under SMP or ccNUMA? Not all Grand Challenge problems require vector processors and not all problems are easily parceled out to swarms of loosely interconnected cluster systems. How broadly does the definition of supercomputing apply?

Wikipedia defines supercomputing as:

A supercomputer is a computer that leads the world in terms of processing capacity, particularly speed of calculation, at the time of its introduction. The term “Super Computing” was first used by New York World newspaper in 1929 to refer to a large custom-built tabulators IBM made for Columbia University.

Seymour Cray described the different approaches in the famous quote: “If you were plowing a field, which would you rather use: Two strong oxen or 1024 chickens?”.

When I worked at Cray Research, Inc. through the 1990′s it was popular to say ‘speeds and feeds’. I/O subsystems themselves where supercomputers as they dedicated their power to feeding the processing systems. Y-MPs, C-90, and T3 systems were certainly world leading systems of their time. For a period of time, Cray defined the field.

Times have changed and chickens are cheaper, stronger, and easier to manage than ever before. The interconnects faster and more reliable. Powerful cluster systems can be built using Commodity off The Shelf (COTS) hardware and Open Source operating systems such as LINUX. Cray said, “Anyone can build a fast CPU. The trick is to build a fast system.”, this is increasingly true as processors have become commodities. In fact, most systems on the Top500 list use processors found in commodity systems.

Does the differentiation between true supercomputing and distributed computing with clusters and grids boil down to the interconnects between processors and systems? According to the Top500 list, 51.2% of the Top500 supercomputers use Gigabit Ethernet to connect systems.

As it stands, it appears the chickens are winning.

(Note: This thought it still developing.)