NumberOfTestWorkers vs LevelOfParallelism

[TopProgrammer77]

I've found two options - NumberOfTestWorkers and LevelOfParallelism that can help to parallelize the test.
But I don't know when to use each option.
Also I don't know that using both all can increase the speed.

[OsirisTerje]

These are the same. If the NumberOfTestWorkers is set, then it overrides the LevelOfParallelism attribute in the source code files.

The NumberOfTestWorkers is an option for the runner (NUnit3TestAdapter/dotnet test) in the first case (NUnit.Console --workers is also the same as this option), whereas the LevelOfParallelism is a source code attribute.

See https://docs.nunit.org/articles/nunit/writing-tests/attributes/levelofparallelism.html