diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index 9155e3cf274535155ad31856164d1c056d83299d..ea31261c955ec70a0e16d088baa3cba98aa97cbf 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Added ActiveSupport::BufferedLogger as a duck-typing alternative (albeit with no formatter) to the Ruby Logger, which provides a very nice speed bump (inspired by Ezra's buffered logger) [DHH]
+
 * Object#instance_exec produces fewer garbage methods.  [Mauricio Fernandez]
 
 * Decode json strings as Dates/Times if they're using a YAML-compatible format.  Closes #9614 [Rick]
diff --git a/activesupport/lib/active_support.rb b/activesupport/lib/active_support.rb
index 9eec6f3b3848c5fcfd80c333e93544c4c7628cca..28424dd6a7d58e674b759763b90d4a7ca76df310 100644
--- a/activesupport/lib/active_support.rb
+++ b/activesupport/lib/active_support.rb
@@ -29,7 +29,10 @@
 require 'active_support/inflector'
 
 require 'active_support/core_ext'
+
 require 'active_support/clean_logger'
+require 'active_support/buffered_logger'
+
 require 'active_support/dependencies'
 require 'active_support/deprecation'
 
diff --git a/activesupport/lib/active_support/buffered_logger.rb b/activesupport/lib/active_support/buffered_logger.rb
new file mode 100644
index 0000000000000000000000000000000000000000..b28f4a5ad382389255315b38ef94ae68f593b1e6
--- /dev/null
+++ b/activesupport/lib/active_support/buffered_logger.rb
@@ -0,0 +1,79 @@
+module ActiveSupport
+  # Inspired by the buffered logger idea by Ezra
+  class BufferedLogger
+    module Severity
+      DEBUG   = 0
+      INFO    = 1
+      WARN    = 2
+      ERROR   = 3
+      FATAL   = 4
+      UNKNOWN = 5
+    end
+    include Severity
+
+    # Set to false to disable the silencer
+    cattr_accessor :silencer
+    self.silencer = true
+
+    # Silences the logger for the duration of the block.
+    def silence(temporary_level = ERROR)
+      if silencer
+        begin
+          old_logger_level, self.level = level, temporary_level
+          yield self
+        ensure
+          self.level = old_logger_level
+        end
+      else
+        yield self
+      end
+    end
+
+    attr_accessor :level, :auto_flushing
+    attr_reader :buffer
+
+    def initialize(log, level = DEBUG)
+      @level         = level
+      @buffer        = ""
+      @auto_flushing = true
+
+      if log.respond_to?(:write)
+        @log = log
+      elsif File.exist?(log)
+        @log = open(log, (File::WRONLY | File::APPEND))
+        @log.sync = true
+      else
+        @log = open(log, (File::WRONLY | File::APPEND | File::CREAT))
+        @log.sync = true
+        @log.write("# Logfile created on %s" % [Time.now.to_s])
+      end
+    end
+
+    for severity in Severity.constants
+      class_eval <<-EOT
+        def #{severity.downcase}(message)
+          return if @level > #{severity}
+          message << "\\n" unless message[-1] == ?\\n
+          @buffer << message
+          flush if auto_flushing
+          message
+        end
+        
+        def #{severity.downcase}?
+          @level == #{severity}
+        end
+      EOT
+    end
+
+    def flush
+      return if @buffer.size == 0
+      @log.write(@buffer.slice!(0..-1))
+    end
+
+    def close
+      flush
+      @log.close if @log.respond_to?(:close)
+      @log = nil
+    end
+  end
+end
\ No newline at end of file
diff --git a/activesupport/lib/active_support/clean_logger.rb b/activesupport/lib/active_support/clean_logger.rb
index 95d4f07f4d6e02809caf91c44519086c0968a19b..0c6de67f8d013f7f545816aceedf47a2bf53d6f5 100644
--- a/activesupport/lib/active_support/clean_logger.rb
+++ b/activesupport/lib/active_support/clean_logger.rb
@@ -11,6 +11,8 @@
 # You can then specify the datetime format, for example:
 #
 #   logger.datetime_format = "%Y-%m-%d"
+#
+# Note: This logger is deprecated in favor of ActiveSupport::BufferedLogger
 class Logger
   # Set to false to disable the silencer
   cattr_accessor :silencer
diff --git a/railties/CHANGELOG b/railties/CHANGELOG
index b015d92060fb1e41fc4ab75f3014d6501501f1fc..3f77a2f37bee8f7fe7e7985da8e54d8ef40e2126 100644
--- a/railties/CHANGELOG
+++ b/railties/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Changed the default logger from Ruby's own Logger with the clean_logger extensions to ActiveSupport::BufferedLogger for performance reasons [DHH]. (You can change it back with config.logger = Logger.new("/path/to/log", level).)
+
 * Added a default 422.html page to be rendered when ActiveRecord::RecordInvalid, ActiveRecord::RecordNotSaved, or ActionController::InvalidAuthenticityToken is raised [DHH]
 
 * Added --skip-fixture option to script/generate model #6862 [sandofsky]
diff --git a/railties/lib/dispatcher.rb b/railties/lib/dispatcher.rb
index cb1289957e931a77e57757ef2f2facd085df71a2..398acb7e973801fe4d42cb5f3236a81ab50b34bf 100644
--- a/railties/lib/dispatcher.rb
+++ b/railties/lib/dispatcher.rb
@@ -38,13 +38,14 @@ def dispatch(cgi = nil, session_options = ActionController::CgiRequest::DEFAULT_
         controller = ActionController::Routing::Routes.recognize(request)
         controller.process(request, response).out(output)
       end
-    rescue Exception => exception  # errors from CGI dispatch
+    rescue Exception => exception # errors from CGI dispatch
       failsafe_response(cgi, output, '500 Internal Server Error', exception) do
         controller ||= (ApplicationController rescue ActionController::Base)
         controller.process_with_exception(request, response, exception).out(output)
       end
     ensure
-      # Do not give a failsafe response here.
+      # Do not give a failsafe response here
+      flush_logger
       reset_after_dispatch
     end
 
@@ -165,9 +166,13 @@ def failsafe_logger
         if defined?(RAILS_DEFAULT_LOGGER) && !RAILS_DEFAULT_LOGGER.nil?
           RAILS_DEFAULT_LOGGER
         else
-          Logger.new($stderr)
+          ActiveSupport::BufferedLogger.new($stderr)
         end
       end
+      
+      def flush_logger
+        RAILS_DEFAULT_LOGGER.flush if defined?(RAILS_DEFAULT_LOGGER) && RAILS_DEFAULT_LOGGER.respond_to?(:flush)
+      end
   end
 end
 
diff --git a/railties/lib/initializer.rb b/railties/lib/initializer.rb
index b9fa9eee01edad699089cb06fda36a93bd8dba90..c2862ee4439dec9cdd480a8d030eeafc7e58e156 100644
--- a/railties/lib/initializer.rb
+++ b/railties/lib/initializer.rb
@@ -240,11 +240,12 @@ def initialize_logger
 
       unless logger = configuration.logger
         begin
-          logger = Logger.new(configuration.log_path)
-          logger.level = Logger.const_get(configuration.log_level.to_s.upcase)
-        rescue StandardError
-          logger = Logger.new(STDERR)
-          logger.level = Logger::WARN
+          logger = ActiveSupport::BufferedLogger.new(configuration.log_path)
+          logger.level = ActiveSupport::BufferedLogger.const_get(configuration.log_level.to_s.upcase)
+          logger.auto_flushing = false if configuration.environment == "production"
+        rescue StandardError =>e
+          logger = ActiveSupport::BufferedLogger.new(STDERR)
+          logger.level = ActiveSupport::BufferedLogger::WARN
           logger.warn(
             "Rails Error: Unable to access log file. Please ensure that #{configuration.log_path} exists and is chmod 0666. " +
             "The log level has been raised to WARN and the output directed to STDERR until the problem is fixed."