Parallel software applications in high-energy physics

Parallel programming allows the speed of computations to be increased by using multiple processors or computers working jointly on the same task. In parallel programming dif culties that are not present in sequential programming can be encountered, for instance communication between processors. The way of writing a parallel program depends strictly on the architecture of a parallel system. An ef cient program of this kind not only performs its computations faster than its sequential version, but also effectively uses the CPU time. Parallel programming has been present in high-energy physics for years. The lecture is an introduction to parallel computing in general. It discusses the motivation for parallel computations, hardware architectures of parallel systems and the key concepts of a parallel programming. It also relates parallel computing to high-energy physics and presents a parallel programming application in the eld, namely PROOF.