diff --git a/NEWS b/NEWS
index 8ce253ee..f2810755 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ Enhancements and new features:
     * Add authprovider for cassandra export (thanks to @EmilienMottet) #1395
     * Curses's browser server list sorting added (thanks to @limfreee) #1396
     * ElasticSearch: add date to index, unbreak object push (thanks to @genevera) # 1438
+    * Performance issue with large folder #1491 
 
 Bugs corrected:
 
diff --git a/conf/glances.conf b/conf/glances.conf
index 1a6880e1..a161be41 100644
--- a/conf/glances.conf
+++ b/conf/glances.conf
@@ -174,10 +174,12 @@ critical=90
 # * careful: optional careful threshold (in MB)
 # * warning: optional warning threshold (in MB)
 # * critical: optional critical threshold (in MB)
+# * refresh: interval in second between two refreshs
 #folder_1_path=/tmp
 #folder_1_careful=2500
 #folder_1_warning=3000
 #folder_1_critical=3500
+#folder_1_refresh=60
 #folder_2_path=/home/nicolargo/Videos
 #folder_2_warning=17000
 #folder_2_critical=20000
diff --git a/docs/aoa/folders.rst b/docs/aoa/folders.rst
index af42efe3..08db2d5c 100644
--- a/docs/aoa/folders.rst
+++ b/docs/aoa/folders.rst
@@ -17,11 +17,12 @@ Each item is defined by:
 - ``careful``: optional careful threshold (in MB)
 - ``warning``: optional warning threshold (in MB)
 - ``critical``: optional critical threshold (in MB)
+- ``refresh``: interval in second between two refresh (default is 30 seconds)
 
 Up to ``10`` items can be defined.
 
-For example, if you want to monitor the ``/tmp`` folder, the following
-definition should do the job:
+For example, if you want to monitor the ``/tmp`` folder every minute,
+the following definition should do the job:
 
 .. code-block:: ini
 
@@ -30,8 +31,10 @@ definition should do the job:
     folder_1_careful=2500
     folder_1_warning=3000
     folder_1_critical=3500
+    folder_1_refresh=60
 
 In client/server mode, the list is defined on the ``server`` side.
 
 .. warning::
-    Do **NOT** define folders containing lot of files and subfolders.
+    Do **NOT** define folders containing lot of files and subfolders or use an
+    huge refresh time...
diff --git a/docs/man/glances.1 b/docs/man/glances.1
index 19980e64..8131c409 100644
--- a/docs/man/glances.1
+++ b/docs/man/glances.1
@@ -1,6 +1,6 @@
 .\" Man page generated from reStructuredText.
 .
-.TH "GLANCES" "1" "Apr 18, 2019" "3.1.1b0" "Glances"
+.TH "GLANCES" "1" "Jun 12, 2019" "3.1.1b0" "Glances"
 .SH NAME
 glances \- An eye on your system
 .
diff --git a/glances/folder_list.py b/glances/folder_list.py
index cbd5df15..262e7610 100644
--- a/glances/folder_list.py
+++ b/glances/folder_list.py
@@ -22,6 +22,7 @@ from __future__ import unicode_literals
 
 import os
 
+from glances.timer import Timer
 from glances.compat import range, nativestr
 from glances.logger import logger
 
@@ -57,11 +58,19 @@ class FolderList(object):
     __folder_list_max_size = 10
     # The folder list
     __folder_list = []
+    # Default refresh time is 30 seconds for this plugins
+    __default_refresh = 30
 
     def __init__(self, config):
         """Init the folder list from the configuration file, if it exists."""
         self.config = config
 
+        # A list of Timer
+        # One timer per folder
+        # default timer is __default_refresh, can be overwrite by folder_1_refresh=600
+        self.timer_folders = []
+        self.first_grab = True
+
         if self.config is not None and self.config.has_section('folders'):
             if scandir_tag:
                 # Process monitoring list
@@ -90,6 +99,12 @@ class FolderList(object):
                 value['path'] = nativestr(value['path'])
 
             # Optional conf keys
+            # Refresh time
+            value['refresh'] = int(self.config.get_value(section,
+                                                         key + 'refresh',
+                                                         default=self.__default_refresh))
+            self.timer_folders.append(Timer(value['refresh']))
+            # Thesholds
             for i in ['careful', 'warning', 'critical']:
                 # Read threshold
                 value[i] = self.config.get_value(section, key + i)
@@ -155,6 +170,9 @@ class FolderList(object):
         # Iter upon the folder list
         for i in range(len(self.get())):
             # Update folder size
+            if not self.first_grab and not self.timer_folders[i].finished():
+                continue
+            # Get folder size
             try:
                 self.__folder_list[i]['size'] = self.__folder_size(self.path(i))
             except OSError as e:
@@ -164,6 +182,11 @@ class FolderList(object):
                     self.__folder_list[i]['size'] = '!'
                 else:
                     self.__folder_list[i]['size'] = '?'
+            # Reset the timer
+            self.timer_folders[i].reset()
+
+        # It is no more the first time...
+        self.first_grab = False
 
         return self.__folder_list