Installing a Native "Apple Silicon" GSAS-II Version on MacOS

After something like 4 months of occasional trial and much error, I was finally able to get GSAS-II to run on a ARM Mac running MacOS 11.2.3.

As I write this (6/24/21), Anaconda is not supporting ARM Macs and the wxpython version of miniforge is broken, so I had to install Python and associated packages with ​homebrew.

Installing Homebrew

See ​this page. Note that access to a Admin level account is a requirement for this. Use these steps:

1. Install command line tools. Use command:

   xcode-select --install
   

2. Log into a admin account (I used su admin in a terminal running as a standard user)
3. Install homebrew using command:

   /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
   

4. To add brew to path, use command:

   eval "$(/opt/homebrew/bin/brew shellenv)"
   

Install stuff with brew

Brew is used to install a bunch of things. Here are the commands I used:

brew install svn
brew install python
brew install scipy
brew install wxpython

Install more stuff with pip

python3 -m pip install -U matplotlib
python3 -m pip install -U pyopengl  

Install GSAS-II

These steps are best done from a user account rather than an admin account. You can log out of the admin account or simply close the terminal window used before and open a new one.

eval "$(/opt/homebrew/bin/brew shellenv)"
mkdir ~/GSASII
cd ~/GSASII
curl https://subversion.xray.aps.anl.gov/pyGSAS/install/bootstrap.py -o bootstrap.py
python3 bootstrap.py

Compiling GSAS-II fortran routines

You probably do not need this. There is now a set of M1 (aka ARM, aka Apple Silicon) binaries in

This was fairly hard and I don't know what steps were required in retrospect. Also, it might have been better to use brew install gfortran scons rather than using miniforge to install gfortran. (I downloaded ​https://github.com/conda-forge/miniforge/releases/latest/download/Miniforge3-MacOSX-arm64.sh from Miniforge3-MacOSX-arm64 link on ​https://github.com/conda-forge/miniforge

bash ~/Downloads/Miniforge3-MacOSX-arm64.sh
source /Users/toby/miniforge3/bin/activate
conda create -n buildg10.2 gfortran=10.2 gfortran_impl_osx-arm64=10.2 scons numpy

I installed all of Xcode to get file headers, but that may not have been needed. I had a lot of problems getting gcc to find them, but that should now be changed in Sconstruct

Speed Benchmarks

These comparisons are for two very different powder refinement cycles with a 2.3 Mh quadcore I7 MacBook Pro (early 2020) with a M1 MacBook Pro (late 2020); Both have 16 Gb.

Intel I7	Apple M1	I7:M1 ratio
4 cores	4 performance
	& 4 efficiency
6.99 s	3.85 s	1.82
106.9 s	57.34	1.86