physical-cpu-count
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    1.0.0 • Public • Published

    physical-cpu-count

    Returns the number of physical CPU cores.

    Example

    const physicalCpuCount = require('physical-cpu-count')
    // 4
     
    const logicalCpuCount = require('os').cpus().length
    // 8

    Use Case

    Working with clusters of Node.js processes it is common to see code using os.cpus().length as the number of child workers to fork. For some workloads this can negatively impact performance on CPUs that use simultaneous multithreading (SMT). Latency is doubled because two processes share the same physical CPU core to get their work done. Additionally there is memory spent for each running worker, as well as time to spawn their processes. It is better to fork no more child processes than there are physical cores.

    Known Limitations

    This module takes a naive approach that only looks at Intel CPUs, and assumes every Intel CPU supports, and has enabled, Hyper-Threading with two threads per physical core. These assumptions are not always correct.

    Power management might also make CPU cores unavailable.

    See also:

    Install

    npm i physical-cpu-count@1.0.0

    Version

    1.0.0

    License

    ISC

    Last publish

    Collaborators

    • seb