3.3.1.1 Modifying the Number of Threads for MKL on Linux
You can change the number of threads to be used by MKL by editing the system environment variable MKL_NUM_THREADS. For example, the following statement in the Bash shell, causes MKL to use 3 threads:
export MKL_NUM_THREADS=3
After setting MKL_NUM_THREADS to 3, the output of Sys.BlasLapack shows a value of 3 for $nthreads.
R> Sys.BlasLapack()
$vendor
[1] "Intel Math Kernel Library (Intel MKL)"
$nthreads
[1] 3