Comment Re:Another nail in the coffin of the Mainframe (Score 2, Informative) 346
Supercomputers are used for high performance technical computing. Mainframes, on the other hand are used when you need high reliability/availability. When someone talks about 5-nines reliability, they are saying a system is up 99.999% of the time - equivalent to a couple minutes per year. The systems that achieve this do what is called fault-tolerant computing. It is done by having integrated redundant hardware along with the appropriate specialized software to deal with it.
You won't find any supercomputer or PC that does this. This is why there will *always* be a market for mainframes. It may not be a huge market, but it's still a market.