Using multiple threads with parallel LINQ

By default, only one thread is used to execute a LINQ query. Parallel LINQ (PLINQ) is an easy way to enable multiple threads to execute a LINQ query.

Good Practice: Do not assume that using parallel threads will improve the performance of your applications. Always measure real-world timings and resource usage.

Creating an app that benefits from multiple threads

To see it in action, we will start with some code that only uses a single thread to calculate Fibonacci numbers for 45 integers. We will use the StopWatch type to measure the change in performance.

We will use operating system tools to monitor the CPU and CPU core usage. If you do not have multiple CPUs or at least multiple cores, then this exercise won't show much!

1. Use your preferred code editor to add a new console app named LinqInParallel to the Chapter11 solution/workspace.
2. In Visual Studio Code, select LinqInParallel as the active...