MKL Optimizations

Developed specifically for science, engineering, and financial computations, Intel™ Math Kernel Library (MKL) is a set of threaded and vectorized math routines that work to accelerate various math functions and applications. Anaconda has packaged MKL-powered binary versions of some of the most popular numerical/scientific Python libraries into MKL Optimizations for improved performance.

MKL Optimizations includes:
  • Speed-boosted NumPy, SciPy, scikit-learn, and NumExpr
  • The packaging of MKL with redistributable binaries in Anaconda for easy access to the MKL runtime library.
  • Python bindings to the low level MKL service functions, which allow for the modification of the number of threads being used during runtime.


In Anaconda versions 2.5 and later, MKL is freely available by default in Anaconda.

If you already have the free Anaconda Python distribution installed, get MKL by upgrading to the latest version:

conda update conda
conda update anaconda

If you do not have Anaconda installed, you can download it here.

Existing MKL licenses can be viewed and removed with the graphical Anaconda Navigator license manager or manually with your operating system.


Anaconda now also includes a small utility package called mkl-service which provides a Python interface to some useful MKL functions that are declared in mkl_service.h, such as setting the number of threads to use.

Uninstalling MKL

MKL takes roughly 100MB and some use cases do not need it, so users can opt out of MKL and instead use OpenBLAS for Linux or the native Accelerate Framework for MacOSX. To opt out, run conda install nomkl and then use conda install to install packages that would normally include MKL or depend on packages that include MKL, such as scipy, numpy, and pandas. Conda will install the non-MKL versions of these packages together with their dependencies. If you are using OS X or Linux, have already installed these packages or already installed all of Anaconda, and wish to switch away from MKL, use the command conda install nomkl numpy scipy scikit-learn numexpr followed by conda remove mkl mkl-service.


If you already have the free Anaconda Python distribution installed and wish to update MKL:

conda update conda
conda update mkl

Dismissing MKL Trial warnings

Because past versions of Anaconda did not include MKL linked binaries by default, some users who have used conda update --all may see an MKL Trial warning or a license expiration error, even though MKL linked packages are now free and installed by default. A license expiration error message may read, “You cannot run MKL without a license any longer.”

To resolve this, set your installation to use the mkl-linked libraries that do not require a license:

conda remove mkl-rt
conda install -f mkl

Then run conda install with the specific packages you choose:

conda install numpy scipy scikit-learn numexpr

or with all of Anaconda:

conda install anaconda

Resolving MKL shared library “permission denied” errors

On Linux platforms that have SELinux enabled, you may encounter security errors like the following:

error while loading shared libraries: <>: cannot restore segment prot after reloc: Permission denied

This is because MKL requires text relocation permissions, which SELinux denies by default. This prevents MKL from being loaded by Numpy, preventing Numpy from being imported.

There are two known solutions to this issue:

  1. Does not require root privileges. Replace MKL with OpenBLAS by issuing the command:

    conda install nomkl numpy scipy scikit-learn numexpr

    You may revert back to the MKL default versions at any time by using:

    conda remove nomkl
    conda install mkl
  2. Requires root privileges. Temporarily disable SELinux enforcement. From a root-privileged terminal enter:

    /usr/sbin/setenforce 0

    NOTE: If you prefer to make this change permanent, in the file /etc/selinux/config change “enforcing” to “disabled” and then reboot.

License Agreement

The MKL Optimizations are included in the free Anaconda python distribution, and have been made available by the terms of the ../anaconda/eula.

Past versions of MKL Optimizations were not freely available in Anaconda, and have been made available separately by the terms of the MKL Optimizations End User License Agreement.