diff --git a/source/reference/program/mongoperf.txt b/source/reference/program/mongoperf.txt
index e6890d4f7d3..b8b1526b981 100644
--- a/source/reference/program/mongoperf.txt
+++ b/source/reference/program/mongoperf.txt
@@ -166,10 +166,10 @@ following form:
 
 In this operation:
 
-- :program:`mongoperf` tests direct physical random read io's, using
+- :program:`mongoperf` tests direct physical random read and write io's, using
   16 concurrent reader threads.
 
-- :program:`mongoperf`  uses a 1 gigabyte test file.
+- :program:`mongoperf`  uses a 10 gigabyte test file.
 
 Consider using ``iostat``, as invoked in the following example to
 monitor I/O performance during the test.