diff --git a/2019-02-05.md b/2019-02-05.md
index 9d13e3e..9ec8dd1 100644
--- a/2019-02-05.md
+++ b/2019-02-05.md
@@ -147,7 +147,7 @@ ly.write("merged_#{flat ? %q/flat/ : %q/deep/}.oas.gz")
 
 ## Performance numbers 
 
-The performance numbers on my laptop are:
+The performance numbers on my laptop (Ubuntu 16, 64 bit) are:
 
 Flat:
 
@@ -214,3 +214,7 @@ But the booleans pay this effort back with a 8x performance boost. That's becaus
 Total runtime of the script on my system is
  * 46s (hierarchical) 
  * 210s (flat)
+
+Another remarkable fact is the memory footprint (maxresident on process on 64 bit)
+ * 518M (hierarchical)
+ * 1.6G (flat)