Petaflops is a unit of measurement used for measuring the performance of a processor's floating point unit, or FPU. It may also be written "petaFLOPS" or "PFLOPS." Since FLOPS stands for "Floating Point Operations Per Second," the term "petaflops" may be either singular (one petaflops) or plural (two or more petaflops). One petaflops is equal to 1,000 teraflops, or 1,000,000,000,000,000 FLOPS.

Petaflops are rarely used to measure a single computer's performance, since only the fastest supercomputers run at more than one petaflops. Therefore, petaflops are more often used when calculating the processing power of multiple computers. Also, since FLOPS only measures floating point calculations, petaflops is not necessarily a good indicator of a computer's overall performance. Other factors, such as the processor's clock speed, the system bus speed, and the amount of RAM may also affect how quickly a computer can perform calculations.