Acknowledgement: This software release is made possible with the funding support from NIH/NIGMS under the grant number R01-GM114365.
Monte Carlo eXtreme, or MCX, is a fast Monte Carlo software package for photon transport simulation in 3D heterogeneous media. It uses Graphics Processing Units (GPU) for massively parallel simulations and offers hundreds times acceleration compared to a traditional single-threaded CPU-based simulation.
This release fully supports NVIDIA Pascal GPUs. The speed comparisons between different generations of NVIDIA GPUs can be found at
MCX v2017.7 (code named "Dark Matter") is a Release Candidate for MCX v1.0. It is a result of numerous improvements developed over the past year, and contains a list of new features and bug fixes. If you are using a previous release, you are strongly recommended to upgrade immediately.
In this new release, the most notable update is the significantly improved MCXStudio - a cross-platform graphical user interface. The new MCXStudio became the single unified GUI for all 3 developed MC simulation packages (MCX/MMC/MCXCL), and is packaged with numerous features - including visual domain designer, 3D rendering of the results, built-in media, detector and source designer, remote execution and many more. A list of video tutorials on how to MCXStudio to design complex simulations can be found at http://mcx.sourceforge.net/cgi-bin/index.cgi?Demo/MCXStudio
In addition, the GPU code was heavily optimized to achieve improved speed and robustness. The new MCX supports all NVIDIA GPU architectures from Fermi to Volta. A number of bugs were fixed, including the crash of MCXLAB when using multiple GPUs, and errors previously on Pascal GPUs, and the incorrect progress bar feature on Windows.
Please visit our website (http://mcx.space) for more detailed documentation, demos and tutorials.
Compared to the previous release (version v2017.3, released in Apr. 2017), MCX v2017.7 gains the following new features and bug fixes:
In the meantime, a number of critical bugs were fixed:
Pre-compiled MCX are provided for Windows (64 bit), Linux (64bit) and Mac OS (64bit). In the case of MCXLAB, mex files for both Matlab and Octave on these platforms are provided. All binaries have been tested on Fermi/Kepler and Maxwell GPUs.
The provided binaries require a Fermi (Compute Capability 2.0) or newer GPU. If you have an older GPU (CC 1.0 or 1.1), you will have to recompile mcx using "make fast".
To install MCX version v2017.7, you need
The CUDA toolkit is no longer required in this release, however, if you run into CUDA errors, please download the latest CUDA driver, you can download from here
In this release, all precompiled binaries, including both mcx executables and mcxlab mex files, have built-in CUDA run-time libraries via static linking. Therefore, downloading/setting CUDA toolkit and the run-time librarie files (cudart.dll/libcudart.so/libcudart.dylib) are no longer needed.
However, if you run into CUDA errors, please first try to update your NVIDIA graphics driver to the latest version
If the latest graphics driver still can not solve the problem, please download the "developer driver" for your GPU. You may download the developer driver as part of the CUDA Toolkit installation package.
To use MCXLAB v2017.7 in GNU Octave, you must install the following:
Be aware, if you have a Maxwell GPU (GTX 980Ti and 980) and plan to run MCX on it, please first test the benchmark script "run_benchmark1.sh" or "run_benchmark1.bat" under the mcx/example folder. You are expected to see ~29,000 photon/ms for 980Ti and 20,000 photon/ms for 980. If your simulation speed is around 1,200 to 1,500 photon/ms, that means you are impacted by a bug in the CUDA driver. Please recompile MCX using CUDA 7.0 or 6.5, update your NVIDIA driver to version 375 or later. For details, please see
Qianqian Fang and David A. Boas, "Monte Carlo Simulation of Photon Migration in 3D Turbid Media Accelerated by Graphics Processing Units," Opt. Express, vol. 17, issue 22, pp. 20178-20190 (2009)