diff --git a/JOURNAL.md b/JOURNAL.md
index c2b819a..08a69fd 100644
--- a/JOURNAL.md
+++ b/JOURNAL.md
@@ -1091,3 +1091,25 @@ fault and the MMU at this point.
 
 Let's make a much simpler program that only allocates once a buffer of N bytes
 and then begins filling it, printing the progress in the output.
+
+### OBSERVATION: Writing to a vector also stops around 58 MiB
+
+    + memtool fill 536870912
+    memtool v0.0.1 - Rodrigo Arias Mallo <rodrigo.arias@bsc.es>
+    mode fill: nbytes=512M, n=134217728
+    written=0K, addr=0x3f9b800020 OK
+    written=4096K, addr=0x3f9bc00020 OK
+    written=8192K, addr=0x3f9c000020 OK
+    written=12288K, addr=0x3f9c400020 OK
+    written=16384K, addr=0x3f9c800020 OK
+    written=20480K, addr=0x3f9cc00020 OK
+    written=24576K, addr=0x3f9d000020 OK
+    written=28672K, addr=0x3f9d400020 OK
+    written=32768K, addr=0x3f9d800020 OK
+    written=36864K, addr=0x3f9dc00020 OK
+    written=40960K, addr=0x3f9e000020 OK
+    written=45056K, addr=0x3f9e400020 OK
+    written=49152K, addr=0x3f9e800020 OK
+    written=53248K, addr=0x3f9ec00020 OK
+    written=57344K, addr=0x3f9f000020 OK
+