diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -594,7 +594,7 @@ coreconfigitem('experimental', 'sparse-r
     default=False,
 )
 coreconfigitem('experimental', 'sparse-read.density-threshold',
-    default=0.25,
+    default=0.50,
 )
 coreconfigitem('experimental', 'sparse-read.min-gap-size',
     default='256K',
diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -625,7 +625,7 @@ class revlog(object):
         self._compengine = 'zlib'
         self._maxdeltachainspan = -1
         self._withsparseread = False
-        self._srdensitythreshold = 0.25
+        self._srdensitythreshold = 0.50
         self._srmingapsize = 262144
 
         mmapindexthreshold = None