2.)

The first reason why regional bank might decide to buy 6 server computers than a supercomputer and it is applicable than a one computer.
The another one is if the bank buy a 6 server computer its because if a computer will not function anymore, there are still five remaining, computers that can work faster than a supercomputer and if the supercomputer will not function anymore, there will be no backup of all the data that have save in the supercomputer and thye cannot retrieve the data anymore..