EDVAC, the first modern stored program computer to be designed, used a central control unit that only interpreted four instructions. All ofthe arithmetic-related instructions were passed on to its arithmetic unit and further decoded there. ENIAC consumed an estimated 174 kW. By comparison, a typical personal computer may use around 400 W;over four hundred times less. ENIAC were able to process between 5and 100 operations per second A modern "commodity" microprocessor (as of 2007 )can process billions of operations per second. and many of these operations are more complicated and useful than early computer operations.