The system for using excess computational power of claim 24 wherein the client is also charged an hourly premium for requesting reliability greater than a set baseline reliability given by the formula: Price per hour for premium reliability = k ??? ??? CN ??? ??? ( ln ??? ??? ( 1 - r ) ln ??? ??? ( 1 - R ) - 1 ) where k is a baseline price per MHz-hour, C is the CPU speed requested of a virtual no