# Global Efficiency

The Global Efficiency (GE) measures the overall quality of the parallelisation.

Typically, inefficiencies in parallel code have two main sources: 1) overheads imposed by the parallel nature of a code (i.e., the Parallel Efficiency: PE); and 2) poor scaling of computation with increasing numbers of processes (i.e., the Computation Scaling: CompS). The Global Efficiency metric is the product of these two sub-metrics:

$GE = PE \times CompS$

In order to fully understand the formulas, you may also visit the glossary of the metrics terms.

Related programs: FFTXlib · juKKR kloop ·