diff --git a/Performance.md b/Performance.md
index 2303557..1fb7a87 100644
--- a/Performance.md
+++ b/Performance.md
@@ -6,12 +6,19 @@ Some basic notes on performance:
 
 The
 [munin graph](http://allmydata.org/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_memstats.html)
-shows our static memory footprint (starting a node but not doing
+shows our static memory footprint on a 32bit machine (starting a node but not doing
 anything with it) to be about 24MB. Uploading one file at a time gets the
 node to about 29MB. (we only process one segment at a time, so peak memory
 consumption occurs when the file is a few MB in size and does not grow beyond
 that). Uploading multiple files at once would increase this.
 
+We also have a [
+[64-bit graph](http://allmydata.org/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_memstats.html), which currently shows a disturbingly large static footprint.
+We've determined that simply importing a few of our support libraries (such
+as Twisted) results in most of this expansion, before the node is ever even
+started. The cause for this is still being investigated: we can think of plenty
+of reasons for it to be 2x, but the results show something closer to 6x.
+
 ## Network Speed
 
 ### Test Results