I imagine that 'supercomputer', like 'mainframe', refers to the architecture of the machine rather than to any absolute measure of performance. A Cray-1 is a supercomputer and this machine is faster than that.
Southampton engineers a Raspberry Pi Supercomputer
Posted Sep 14, 2012 16:18 UTC (Fri) by andrel (subscriber, #5166)
[Link]
Specifically, a supercomputer has a balanced architecture. In a true supercomputer the I/O, memory, and network subsystems are capable of keeping the CPUs going at full speed.
This system doesn't have that sort of architecture.
Southampton engineers a Raspberry Pi Supercomputer
Posted Sep 14, 2012 22:14 UTC (Fri) by ballombe (subscriber, #9523)
[Link]
You forgot the most important: the cooling system.
No mention of it either.