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multithreadingjava-8jvmjava-streamhyperthreading

Does number logical CPUs impact Java8 Streams performance?

While processing parallel streams JVM spins up number of threads equal to number of cores. How does the number of logical CPUs impact the performance? Does the degree of parallelism increase with the number of logical CPUs just like number of cores?

Solution

  • java.util.stream.Stream is an interface and the API contract does not specify how parallel streams should be parallelized.

    The most commonly used OpenJDK implementation currently happens to use the ForkJoin common pool, except when it does not.