diff --git modules/rdf/rdf.module modules/rdf/rdf.module
index 1c231f3..157af4c 100644
--- modules/rdf/rdf.module
+++ modules/rdf/rdf.module
@@ -523,17 +523,45 @@ function rdf_preprocess_username(&$variables) {
  */
 function rdf_preprocess_comment(&$variables) {
   $comment = $variables['comment'];
+
+  // Centralizes and caches variables which are expensive to generate.
+  static $cdata;
+  if (empty($cdata)) {
+    // Attempt to load data for the comments to be displayed from cache.
+    $node = node_load($comment->nid);
+    $mode = variable_get('comment_default_mode_' . $node->type, COMMENT_MODE_THREADED);
+    $comments_per_page = variable_get('comment_default_per_page_' . $node->type, 50);
+    if ($cids = comment_get_thread($node, $mode, $comments_per_page)) {
+      foreach ($cids as $k => $cid) {
+        $cids[$k] = 'comment:' . $cid;
+      }
+      $cdata = cache_get_multiple($cids, 'cache');
+    }
+  }
+
+  $cid = 'comment:' . $comment->cid;
+  if (!empty($cdata[$cid])) {
+    $v = $cdata[$cid]->data;
+  }
+  else {
+		$v['url1'] = url('comment/' . $comment->cid, array('fragment' => 'comment-' . $comment->cid));
+		$v['rdfa1'] = rdf_rdfa_attributes($comment->rdf_mapping['created'], $comment->created);
+		$v['url2'] = url('node/' . $comment->nid);
+		$v['url3'] = url('comment/' . $comment->pid, array('fragment' => 'comment-' . $comment->pid));
+    cache_set($cid, $v);
+  }
+
   if (!empty($comment->rdf_mapping['rdftype'])) {
     // Adds RDFa markup to the comment container. The about attribute specifies
     // the URI of the resource described within the HTML element, while the
     // typeof attribute indicates its RDF type (e.g. sioc:Post, etc.).
-    $variables['attributes_array']['about'] = url('comment/' . $comment->cid, array('fragment' => 'comment-' . $comment->cid));
+    $variables['attributes_array']['about'] = $v['url1'];
     $variables['attributes_array']['typeof'] = $comment->rdf_mapping['rdftype'];
   }
 
   // Adds RDFa markup for the date of the comment.
   if (!empty($comment->rdf_mapping['created'])) {
-    $date_attributes_array = rdf_rdfa_attributes($comment->rdf_mapping['created'], $comment->created);
+    $date_attributes_array = $v['rdfa1'];
     $variables['rdf_template_variable_attributes_array']['created'] = $date_attributes_array;
   }
   // Adds RDFa markup for the relation between the comment and its author.
@@ -561,13 +589,13 @@ function rdf_preprocess_comment(&$variables) {
   if (!empty($comment->rdf_mapping['pid'])) {
     // Relation to parent node.
     $parent_node_attributes['rel'] = $comment->rdf_mapping['pid']['predicates'];
-    $parent_node_attributes['resource'] = url('node/' . $comment->nid);
+    $parent_node_attributes['resource'] = $v['url2'];
     $variables['rdf_metadata_attributes_array'][] = $parent_node_attributes;
 
     // Relation to parent comment if it exists.
     if ($comment->pid != 0) {
       $parent_comment_attributes['rel'] = $comment->rdf_mapping['pid']['predicates'];
-      $parent_comment_attributes['resource'] = url('comment/' . $comment->pid, array('fragment' => 'comment-' . $comment->pid));
+      $parent_comment_attributes['resource'] = $v['url3'];
       $variables['rdf_metadata_attributes_array'][] = $parent_comment_attributes;
     }
   }