Instructions per cycle

The unit instructions per cycle (IPC) is the number of from a processor in one clock cycle executable instructions.

It is usually about an average value, since the number of instructions executed per clock cycle varies in most processor architectures. Simple additions can be performed faster, for example, as a set of floating point instructions. To calculate a large number of commands is usually performed and the required clock cycles (which arise from the processor clock and the time needed ) divided.

Konrad Zuse's Z1 had for example a ( unaveraged ) IPC range of 0.05 to 1

This value serves as a measure of the efficiency of an architecture, because the product of IPC and clock frequency gives the number of instructions executed per second commands ( instructions per second). Thus, a processor with IPC = 1 and f = 500 MHz theoretically run as many commands as a second with IPC = 0.5 and f = 1000 MHz. However, limiting factors such as pipelining comparability considerably a.

Should also be noted is still that some manufacturers with a "Cycle " or " clock cycle " does not mean the period of the clock signal, but the same multiples thereof.

In the literature one often finds the inverse, Cycles per Instruction ( CPI).

• Hardware
• Technical computer science
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