Performance seems to have two meanings:
1) The speed at which a computer operates, either theoretically (for example, using a formula for calculating Mtops - millions of theoretical instructions per second) or by counting operations or instructions performed (for example, ( MIPS ) - millions of instructions per second) during a benchmark test. The benchmark test usually involves some combination of work that attempts to imitate the kinds of work the computer does during actual use. Sometimes performance is expressed for each of several different benchmarks.
2) The total effectiveness of a computer system, including throughput , individual response time , and availability.