The effective performance of a computer. It can be expressed in MIPS (millions of instructions per second), clock speed (1 Ghz, 2 Ghz) and in word or bus size, (16-bit, 32-bit, etc.). However, as with automobile horsepower and the number of cylinders, such specifications are only guidelines. Real power is whether it gets the job done in the required time. Software Power A software program is called "powerful" if it has a large number of features.