diff --git a/app/models/commit.rb b/app/models/commit.rb
index 17d41f27f34853addb36d6ef6a3884ff60e911f8..daba5414afa520f06a435245c21e814b7902a356 100644
--- a/app/models/commit.rb
+++ b/app/models/commit.rb
@@ -89,7 +89,14 @@ class Commit
       if first && last
         result[:same] = (first.id == last.id)
         result[:commits] = project.repo.commits_between(last.id, first.id).map {|c| Commit.new(c)}
-        result[:diffs] = project.repo.diff(last.id, first.id) rescue []
+
+        # Dont load diff for 100+ commits
+        result[:diffs] = if result[:commits].size > 100
+                           []
+                         else
+                           project.repo.diff(last.id, first.id) rescue []
+                         end
+
         result[:commit] = Commit.new(first)
       end
 
diff --git a/app/views/compare/show.html.haml b/app/views/compare/show.html.haml
index d8ea3727d57a7353746a83372d5bcc996ceba493..476be2550af36754eedf66be4cfe6bc845f3193b 100644
--- a/app/views/compare/show.html.haml
+++ b/app/views/compare/show.html.haml
@@ -6,6 +6,12 @@
 
 = render "form"
 
+- if @commits.size > 100
+  .alert.alert-block
+    %p
+      %strong Warning! This comparison include 100+ commits.
+    %p To prevent performance issue we dont show diff information.
+
 - if @commits.present?
   %div.ui-box
     %h5.title