From 6b3ed0474c555071cbfd64f36da92fab940da45f Mon Sep 17 00:00:00 2001
From: Hugo Locurcio <hugo.locurcio@hugo.pro>
Date: Wed, 4 Mar 2020 09:47:43 +0100
Subject: [PATCH] Mention RAM requirements for building using Sphinx

This closes #3239.
---
 README.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/README.md b/README.md
index 88b8daf94..0d629cbbd 100644
--- a/README.md
+++ b/README.md
@@ -63,6 +63,16 @@ or:
 make SPHINXBUILD=~/.local/bin/sphinx-build html
 ```
 
+Building the documentation requires at least 8 GB of RAM to be done without swapping. If you have at least 16 GB of RAM, you can speed up compilation by using:
+
+```bash
+# On Linux/macOS
+make html SPHINXOPTS=-j2
+
+# On Windows
+set SPHINXOPTS=-j2 && make html
+```
+
 The compilation might take some time as the `classes/` folder contains many files to parse.
 
 In case of a `MemoryError` or `EOFError`, you can remove the `classes/` folder and run `make` again. This will drop the class references from the final HTML documentation but will keep the rest intact. Make sure to avoid using `git add .` in this case when working on a pull request, or the whole `classes/` folder will be removed when you make a commit. See [#3157](https://github.com/godotengine/godot-docs/issues/3157) for more details.