doc: Add note about memory reqs for compilation

laanwj · laanwj · commit 4babd0813788 · 2014-03-31T06:02:35.000+02:00
diff --git a/doc/build-unix.md b/doc/build-unix.md
@@ -52,6 +52,13 @@ Licenses of statically linked libraries:
 -  protobuf      2.5.0
 -  libqrencode   3.2.0
 
+System requirements
+--------------------
+
+C++ compilers are memory-hungry. It is recommended to have at least 1 GB of
+memory available when compiling Bitcoin Core. With 512MB of memory or less
+compilation will take much longer due to swap thrashing.
+
 Dependency Build Instructions: Ubuntu & Debian
 ----------------------------------------------
 Build requirements:
