Build MXNet from Source

NOTE: For MXNet with Python installation, please refer to the new install guide.

This document explains how to build MXNet from sources. Building MXNet from sources is a 2 step process.

  1. Build the MXNet shared library,, from C++ source files
  2. Install the language binding for MXNet. MXNet supports - C++, Scala, R, and Julia.

Build the shared library


You need C++ build tools and BLAS library to build MXNet shared library. If you want to run MXNet on GPUs, you need to install CUDA and CuDNN.

C++ build tools

  1. A C++ compiler that supports C++ 11. G++ (4.8 or later) or Clang is required.
  2. Git for downloading the sources from Github repository.
  3. GNU Make (cmake for Windows) to build the library.

Select your preferences and follow the instructions to install MXNet from sources.

Then select the Linux distribution:

  • Ubuntu for systems supporting the apt-get package management program
  • CentOS for systems supporting the yum package management program
  • Others for general Linux-like systems building dependencies from scratch.

Install build tools and git on Ubuntu >= 13.10 and Debian >= 8.

sudo apt-get update && sudo apt-get install build-essential git

Install build tools and git on CentOS >= 7 and Fedora >= 19.

sudo yum groupinstall -y "Development Tools" && sudo yum install -y git

Installing both git and make by following instructions on the websites is straightforward. Here we provide the instructions to build gcc-4.8 from source codes.

  1. Install the 32-bit libc with one of the following system-specific commands:
   sudo apt-get install libc6-dev-i386 # In Ubuntu
   sudo yum install glibc-devel.i686   # In RHEL (Red Hat Linux)
   sudo yum install glibc-devel.i386   # In CentOS 5.8
   sudo yum install glibc-devel.i686   # In CentOS 6/7
  1. Download and extract the gcc source code with the prerequisites:
   tar -zxf gcc-4.8.5.tar.gz
   cd gcc-4.8.5
  1. Build gcc by using 10 threads and then install to /usr/local
   mkdir release && cd release
   ../configure --prefix=/usr/local --enable-languages=c,c++
   make -j10
   sudo make install
  1. Add the lib path to your configure file such as ~/.bashrc:
   export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/usr/local/lib64
  1. If Microsoft Visual Studio 2015 is not already installed, download and install it. You can download and install the free community edition.
  2. Download and Install CMake if it is not already installed.

Install Xcode.

BLAS library

MXNet relies on the BLAS (Basic Linear Algebra Subprograms) library for numerical computations. You can install any one among ATLAS, OpenBLAS and MKL.

```bash sudo apt-get install libatlas-base-dev ```
```bash sudo yum install atlas-devel ```

You can follow this link to build OpenBlas from source.

macOS users can skip this step as xcode ships with a BLAS library.

  1. Download pre-built binaries for OpenBLAS
  2. Set the environment variable OpenBLAS_HOME to point to the OpenBLAS directory that contains the include/ and lib/ directories. Typically, you can find the directory in C:\Program files (x86)\OpenBLAS\.

Optional: OpenCV for Image Loading and Augmentation

```bash sudo apt-get install libopencv-dev ```
```bash sudo apt-get install opencv-devel ```

To build OpenCV from source code, you need the cmake library.

  1. If you don’t have cmake or if your version of cmake is earlier than 3.6.1, run the following commands to install a newer version of cmake:
   tar -zxvf cmake-3.6.1-Linux-x86_64.tar.gz
   alias cmake="cmake-3.6.1-Linux-x86_64/bin/cmake"
  1. To download and extract the OpenCV source code, run the following commands:
   unzip 2.4.13
   cd opencv-2.4.13
   mkdir release
   cd release/
  1. Build OpenCV. The following commands build OpenCV with 10 threads. We disabled GPU support, which might significantly slow down an MXNet program running on a GPU processor. It also disables 1394 which might generate a warning. Then install it on /usr/local.
   make -j10
   sudo make install
  1. Add the lib path to your configuration such as ~/.bashrc.
   export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig/

First download and install OpenCV, then set the environment variable OpenCV_DIR to point to the OpenCV build directory.

Optional: CUDA/cuDNN for Nvidia GPUs

MXNet is compatible with both CUDA 7.5 and 8.0. It is recommended to use cuDNN 5.

Install CUDA 7.5 and cuDNN 5 on Ubuntu 14.04

sudo dpkg -i cuda-repo-ubuntu1404_7.5-18_amd64.deb
echo "deb /" | sudo tee /etc/apt/sources.list.d/nvidia-ml.list
sudo apt-get update
sudo apt-get install -y linux-image-extra-`uname -r` linux-headers-`uname -r` linux-image-`uname -r`
sudo apt-get install -y cuda libcudnn5-dev=5.0.5-1+cuda7.5


First clone the recent codes

git clone --recursive
cd mxnet

File make/ contains all the compilation options. You can edit it and then make. There are some example build options

If you want to build MXNet with C++ language binding, please make sure you read Build the C++ package first.

  • Build without using OpenCV. -j runs multiple jobs against multi-core CPUs.
  make -j USE_OPENCV=0
  • Build with both GPU and OpenCV support
  make -j USE_BLAS=openblas USE_CUDA=1 USE_CUDA_PATH=/usr/local/cuda USE_CUDNN=1
  • Build with the default BLAS library and clang installed with xcode (OPENMP is disabled because it is not supported in default by clang).
  make -j USE_BLAS=apple USE_OPENCV=0 USE_OPENMP=0

Use CMake to create a Visual Studio solution in ./build.

In Visual Studio, open the solution file,.sln, and compile it. These commands produce a library called mxnet.dll in the ./build/Release/ or ./build/Debug folder.

Build MXNet using NCCL

  • Download and install the latest NCCL library from NVIDIA.
  • Note the directory path in which NCCL libraries and header files are installed.
  • Ensure that the installation directory contains lib and include folders.
  • Ensure that the prerequisites for using NCCL such as Cuda libraries are met.
  • Append the file with following, in addition to the CUDA related options.
  • USE_NCCL=1
  • USE_NCCL_PATH=path-to-nccl-installation-folder
echo "USE_NCCL=1" >> make/
echo "USE_NCCP_PATH=path-to-nccl-installation-folder" >> make/
cp make/ .
  • Run make command
make -j"$(nproc)"


  • Follow the steps to install MXNet Python binding.
  • Comment the following line in file at incubator-mxnet/tests/python/gpu/
@unittest.skip("Test requires NCCL library installed and enabled during build")
  • Run script as follows. The test should complete. It does not produce any output.
nosetests --verbose tests/python/gpu/

Recommendation for best performance

It is recommended to set environment variable NCCL_LAUNCH_MODE to PARALLEL when using NCCL version 2.1 or newer.

Build the C++ package

The C++ package has the same prerequisites as the MXNet library, you should also have python installed. (Both python 2 and 3 are supported)

To enable C++ package, just add USE_CPP_PACKAGE=1 in the build options when building the MXNet shared library.

Build the R package

The R package requires R to be installed.

Follow the below instructions to install the latest R on Ubuntu 14.04 (trusty) and also the libraries used to build other R package dependencies.

echo "deb trusty/" >> /etc/apt/sources.list
gpg --keyserver --recv-key E084DAB9
gpg -a --export E084DAB9 | apt-key add -

apt-get update
apt-get install -y r-base r-base-dev libxml2-dev libxt-dev libssl-dev

Install the required R package dependencies:

cd R-package
Rscript -e "install.packages('devtools', repo = '')"
Rscript -e "library(devtools); library(methods); options(repos=c(CRAN='')); install_deps(dependencies = TRUE)"

Next, build and install the MXNet R package:

cd ..
make rpkg

Build the Scala package

Both JDK and Maven are required to build the Scala package.

```bash apt-get install -y software-properties-common add-apt-repository -y ppa:webupd8team/java apt-get update echo "oracle-java8-installer shared/accepted-oracle-license-v1-1 select true" | debconf-set-selections apt-get install -y oracle-java8-installer apt-get install -y oracle-java8-set-default apt-get install -y maven ```

The following command builds the .jar package:

make scalapkg

which can be found by ls scala-package/assembly/*/target/*SNAPSHOT.jar.

Optionally, we can install Scala for the interactive interface.

```bash wget dpkg -i scala-2.11.8.deb rm scala-2.11.8.deb ```

Then we can start scala with mxnet imported by

scala -cp scala-package/assembly/*/target/*SNAPSHOT.jar

Build the Julia package

We need to first install Julia.

The following commands install Julia 0.5.1

wget -q
tar -zxf julia-0.5.1-linux-x86_64.tar.gz
rm julia-0.5.1-linux-x86_64.tar.gz
ln -s $(pwd)/julia-6445c82d00/bin/julia /usr/bin/julia

Next set the environment variable MXNET_HOME=/path/to/mxnet so that Julia can find the pre-built library.

Install the Julia package for MXNet with:

julia -e 'Pkg.add("MXNet")'

Build the Perl package

Run the following command from the MXNet source root directory to build the MXNet Perl package:

    sudo apt-get install libmouse-perl pdl cpanminus swig libgraphviz-perl
    cpanm -q -L "${HOME}/perl5" Function::Parameters Hash::Ordered PDL::CCS

    export LD_LIBRARY_PATH=${MXNET_HOME}/lib
    export PERL5LIB=${HOME}/perl5/lib/perl5

    cd ${MXNET_HOME}/perl-package/AI-MXNetCAPI/
    perl Makefile.PL INSTALL_BASE=${HOME}/perl5
    make install

    cd ${MXNET_HOME}/perl-package/AI-NNVMCAPI/
    perl Makefile.PL INSTALL_BASE=${HOME}/perl5
    make install

    cd ${MXNET_HOME}/perl-package/AI-MXNet/
    perl Makefile.PL INSTALL_BASE=${HOME}/perl5
    make install