How to configure a maximum number of threads in a Parallel.For

Question

This is the example microsoft presents for the parallel for, and I'd like to know how configure a maximum number of threads for this code.

     // A basic matrix multiplication.      // Parallelize the outer loop to partition the source array by rows.      System.Threading.Tasks.Parallel.For(0, matARows, i =>      {         for (int j = 0; j < matBCols; j++)         {            // Use a temporary to improve parallel performance.            double temp = 0;            for (int k = 0; k < matACols; k++)            {               temp += matA[i, k] * matB[k, j];            }            result[i, j] = temp;         }      }); // Parallel.For 

Answer 1

You need to specify a ParallelOptions value with a MaxDegreeOfParallelism:

For example:

Parallel.For(0, 10, new ParallelOptions { MaxDegreeOfParallelism = 4 }, count => {     Console.WriteLine(count); }); 

Answer 2

Use MaxDegreeOfParalelism property for running the loop

Parallel.For(0, 1000, new ParallelOptions { MaxDegreeOfParallelism = 2 }, ...);