## Improve parallelism

This guide introduces the different options for parallelism in **Concrete** and how to utilize them to improve the execution time of **Concrete** circuits.

Modern CPUs have multiple cores to perform computation and utilizing multiple cores is a great way to boost performance.

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There are two kinds of parallelism in **Concrete**:
- Loop parallelism to make tensor operations parallel, achieved by using [OpenMP](https://www.openmp.org/)
- Dataflow parallelism to make independent operations parallel, achieved by using [HPX](https://hpx.stellar-group.org/)
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Loop parallelism is enabled by default, as it's supported on all platforms. Dataflow parallelism however is only supported on Linux, hence not enabled by default.