Can't use more than 2 cores with microsoft R Open RRS feed

  • Question

  • I recently installed Microsoft R Open but this message appears at startup of R:

    "Multithreaded BLAS/LAPACK libraries detected. Using 2 cores for math algorithms."

    How can i change this to 3 or 4 cores? 

    Thank you 

    Saturday, October 15, 2016 10:35 AM

All replies

  • parallel::detectCores() will tell you how many cores you have. Keep in mind that most 

    consumer processors have 2 cores, each with 2 virtual cores (so...4 "cores" total). The detectCores()

    will tell you how many non-virtual cores you have.

    Hope this helps,


    Thursday, October 20, 2016 2:03 PM
  • Remember to set logical=FALSE parameter to parallel::detectCores() to detect physical cores only. You can use setMKLthreads to change number of cores used.

    > getMKLthreads()

    [1] 2

    > parallel::detectCores()

    [1] 4

    > setMKLthreads(4)

    Number of threads at maximum: no change has been made.

    > parallel::detectCores(logical =


    [1] 2


    Wednesday, November 2, 2016 10:02 AM