diff --git a/labs/config/config.controller b/labs/config/config.controller
index 89577e56..384e7aec 100644
--- a/labs/config/config.controller
+++ b/labs/config/config.controller
@@ -12,7 +12,8 @@ NET_IF_0=nat
 NET_IF_1=MGMT_NET
 NET_IF_2=API_NET
 
-# Controller is running most of the services; it needs more than 512 MB RAM
+# Controller node is running many services. It needs 1 GB RAM for better
+# performance.
 VM_MEM=1024
 
 # Override number of virtual CPUs (default is 1)