diff --git a/src/applications/cache/spec/PhabricatorDataCacheSpec.php b/src/applications/cache/spec/PhabricatorDataCacheSpec.php
--- a/src/applications/cache/spec/PhabricatorDataCacheSpec.php
+++ b/src/applications/cache/spec/PhabricatorDataCacheSpec.php
@@ -2,6 +2,17 @@
 
 final class PhabricatorDataCacheSpec extends PhabricatorCacheSpec {
 
+  private $cacheSummary;
+
+  public function setCacheSummary(array $cache_summary) {
+    $this->cacheSummary = $cache_summary;
+    return $this;
+  }
+
+  public function getCacheSummary() {
+    return $this->cacheSummary;
+  }
+
   public static function getActiveCacheSpec() {
     $spec = new PhabricatorDataCacheSpec();
     // NOTE: If APCu is installed, it reports that APC is installed.
@@ -79,6 +90,43 @@
     $info = apc_cache_info('user');
     $spec->setUsedMemory($info['mem_size']);
     $spec->setEntryCount(count($info['cache_list']));
+
+    $cache = $info['cache_list'];
+    $state = array();
+    foreach ($cache as $item) {
+      $key = self::getKeyPattern($item['info']);
+      if (empty($state[$key])) {
+        $state[$key] = array(
+          'max' => 0,
+          'total' => 0,
+          'count' => 0,
+        );
+      }
+      $state[$key]['max'] = max($state[$key]['max'], $item['mem_size']);
+      $state[$key]['total'] += $item['mem_size'];
+      $state[$key]['count']++;
+    }
+
+    $spec->setCacheSummary($state);
+  }
+
+  private static function getKeyPattern($key) {
+    // If this key isn't in the current cache namespace, don't reveal any
+    // information about it.
+    $namespace = PhabricatorEnv::getEnvConfig('phabricator.cache-namespace');
+    if (strncmp($key, $namespace.':', strlen($namespace) + 1)) {
+      return '<other-namespace>';
+    }
+
+    $key = preg_replace('/(?<![a-zA-Z])\d+(?![a-zA-Z])/', 'N', $key);
+    $key = preg_replace('/PHID-[A-Z]{4}-[a-z0-9]{20}/', 'PHID', $key);
+
+    // TODO: We should probably standardize how digests get embedded into cache
+    // keys to make this rule more generic.
+    $key = preg_replace('/:celerity:.*$/', ':celerity:X', $key);
+    $key = preg_replace('/:pkcs8:.*$/', ':pkcs8:X', $key);
+
+    return $key;
   }
 
 }
diff --git a/src/applications/config/controller/PhabricatorConfigCacheController.php b/src/applications/config/controller/PhabricatorConfigCacheController.php
--- a/src/applications/config/controller/PhabricatorConfigCacheController.php
+++ b/src/applications/config/controller/PhabricatorConfigCacheController.php
@@ -52,9 +52,48 @@
 
     $this->renderCommonProperties($properties, $cache);
 
+    $table = null;
+    if ($cache->getName() !== null) {
+      $total_memory = $cache->getTotalMemory();
+
+      $summary = $cache->getCacheSummary();
+      $summary = isort($summary, 'total');
+      $summary = array_reverse($summary, true);
+
+      $rows = array();
+      foreach ($summary as $key => $info) {
+        $rows[] = array(
+          $key,
+          pht('%s', new PhutilNumber($info['count'])),
+          phutil_format_bytes($info['max']),
+          phutil_format_bytes($info['total']),
+          sprintf('%.1f%%', (100 * ($info['total'] / $total_memory))),
+        );
+      }
+
+      $table = id(new AphrontTableView($rows))
+        ->setHeaders(
+          array(
+            pht('Pattern'),
+            pht('Count'),
+            pht('Largest'),
+            pht('Total'),
+            pht('Usage'),
+          ))
+        ->setColumnClasses(
+          array(
+            'wide',
+            'n',
+            'n',
+            'n',
+            'n',
+          ));
+    }
+
     return id(new PHUIObjectBoxView())
       ->setHeaderText(pht('Data Cache'))
-      ->addPropertyList($properties);
+      ->addPropertyList($properties)
+      ->appendChild($table);
   }
 
   private function renderCommonProperties(