Clarify compiler requirements

README.md

@@ -17,9 +17,11 @@ For business inquiries, please visit our website and submit the form: [NVIDIA Re
 
 ## Requirements
 
-- Both Windows and Linux are supported.
 - An __NVIDIA GPU__; tensor cores increase performance when available. All shown results come from an RTX 3090.
-- __[CUDA](https://developer.nvidia.com/cuda-toolkit) v10.2 or higher__, a __C++14__ capable compiler, and __[CMake](https://cmake.org/) v3.19 or higher__.
+- A __C++14__ capable compiler. The following choices are recommended and have been tested:
+  - __Windows:__ Visual Studio 2019
+  - __Linux:__ GCC/G++ 7.5 or higher
+- __[CUDA](https://developer.nvidia.com/cuda-toolkit) v10.2 or higher__ and __[CMake](https://cmake.org/) v3.19 or higher__.
 - __(optional) [Python](https://www.python.org/) 3.7 or higher__ for interactive bindings. Also, run `pip install -r requirements.txt`.
   - On some machines, `pyexr` refuses to install via `pip`. This can be resolved by installing OpenEXR from [here](https://www.lfd.uci.edu/~gohlke/pythonlibs/#openexr).
 - __(optional) [OptiX](https://developer.nvidia.com/optix) 7.3 or higher__ for faster mesh SDF training. Set the environment variable `OptiX_INSTALL_DIR` to the installation directory if it is not discovered automatically.