diff --git a/src/calibre/library/caches.py b/src/calibre/library/caches.py
index 235584b9f7..8261ca40fb 100644
--- a/src/calibre/library/caches.py
+++ b/src/calibre/library/caches.py
@@ -28,6 +28,7 @@ class MetadataBackup(Thread): # {{{
         self.daemon = True
         self.db = db
         self.dump_func = dump_func
+        self.dump_queue = Queue()
         self.keep_running = True
 
     def stop(self):
@@ -42,13 +43,32 @@ class MetadataBackup(Thread): # {{{
             except:
                 # Happens during interpreter shutdown
                 break
-            if self.dump_func([id_]) is None:
+            if self.dump_func([id_], dump_queue=self.dump_queue) is None:
                 # An exception occurred in dump_func, retry once
-                prints('Failed to backup metadata for id:', id_, 'once')
+                prints('Failed to get backup metadata for id:', id_, 'once')
                 time.sleep(2)
-                if not self.dump_func([id_]):
-                    prints('Failed to backup metadata for id:', id_, 'again, giving up')
-            time.sleep(0.9) # Limit to one per second
+                if not self.dump_func([id_], dump_queue=self.dump_queue):
+                    prints('Failed to get backup metadata for id:', id_, 'again, giving up')
+            while True:
+                try:
+                    path, raw = self.dump_queue.get_nowait()
+                except:
+                    break
+                else:
+                    try:
+                        with open(path, 'wb') as f:
+                            f.write(raw)
+                    except:
+                        prints('Failed to write backup metadata for id:', id_, 'once')
+                        time.sleep(2)
+                        try:
+                            with open(path, 'wb') as f:
+                                f.write(raw)
+                        except:
+                            prints('Failed to write backup metadata for id:', id_,
+                                    'again, giving up')
+
+            time.sleep(0.2) # Limit to five per second
 
 # }}}
 
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index ee7c3206bf..61c52cf6b7 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -566,7 +566,8 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
     def metadata_for_field(self, key):
         return self.field_metadata[key]
 
-    def dump_metadata(self, book_ids=None, remove_from_dirtied=True, commit=True):
+    def dump_metadata(self, book_ids=None, remove_from_dirtied=True,
+            commit=True, dump_queue=None):
         'Write metadata for each record to an individual OPF file'
         if book_ids is None:
             book_ids = [x[0] for x in self.conn.get(
@@ -580,9 +581,13 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             # cover is set/removed
             mi.cover = 'cover.jpg'
             raw = metadata_to_opf(mi)
-            path = self.abspath(book_id, index_is_id=True)
-            with open(os.path.join(path, 'metadata.opf'), 'wb') as f:
-                f.write(raw)
+            path = os.path.join(self.abspath(book_id, index_is_id=True),
+                    'metadata.opf')
+            if dump_queue is None:
+                with open(path, 'wb') as f:
+                    f.write(raw)
+            else:
+                dump_queue.put((path, raw))
             if remove_from_dirtied:
                 self.conn.execute('DELETE FROM metadata_dirtied WHERE book=?',
                         (book_id,))