diff --git a/doc/source/admin/drivers/fake.rst b/doc/source/admin/drivers/fake.rst
index ea7d7ef4ca..2e2cc355e4 100644
--- a/doc/source/admin/drivers/fake.rst
+++ b/doc/source/admin/drivers/fake.rst
@@ -23,6 +23,30 @@ Development
 Developers can use ``fake-hardware`` hardware-type to mock out nodes for
 testing without those nodes needing to exist with physical or virtual hardware.
 
+Scale testing
+-------------
+The ``fake`` drivers have a configurable delay in seconds which will result in
+those operations taking that long to complete. Two comma-delimited values will
+result in a delay with a triangular random distribution, weighted on the first
+value. These delays are applied to operations which typically block in other
+drivers. This allows more realistic scenarios to be arranged for performance and
+functional testing of an Ironic service without requiring real bare metal or
+faking at the BMC protocol level.
+
+.. code-block:: ini
+
+    [fake]
+    power_delay = 5
+    boot_delay = 10
+    deploy_delay = 60,360
+    vendor_delay = 1
+    management_delay = 5
+    inspect_delay = 360,480
+    raid_delay = 10
+    bios_delay = 5
+    storage_delay = 10
+    rescue_delay = 120
+
 Adoption
 --------
 Some OpenStack deployers have used ``fake`` interfaces in Ironic to allow an