diff --git a/bench/bench-flathashmap.cpp b/bench/bench-flathashmap.cpp
new file mode 100644
index 00000000..f7b0705c
--- /dev/null
+++ b/bench/bench-flathashmap.cpp
@@ -0,0 +1,124 @@
+// Need recent gcc
+#define NDEBUG
+
+#include <vector>
+#include <list>
+#include <iterator>
+#include <map>
+#include <set>
+#include <unordered_map>
+#include <algorithm>
+#include <string>
+#include <sstream>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+
+#include "flat_hash_map.hpp"
+
+using namespace ska;
+using namespace std;
+
+#include "common.h"
+
+/********************************************************************************************/
+
+static void
+test_dict2(unsigned long  n)
+{
+  flat_hash_map<unsigned long, unsigned long> dict;
+  for (size_t i = 0; i < n; i++) {
+    dict[rand_get()] = rand_get();
+  }
+  rand_init();
+  unsigned int s = 0;
+  for (size_t i = 0; i < n; i++) {
+    flat_hash_map<unsigned long, unsigned long>::iterator it = dict.find(rand_get());
+    if (it != dict.end())
+      s += it->second;
+  }
+  g_result = s;
+}
+
+/********************************************************************************************/
+struct char_array_s {
+  char a[256];
+  char_array_s () { a[0] = 0 ; }
+  char_array_s ( const char_array_s & other) { strcpy(a, other.a); }
+  bool operator==(const char_array_s &other) const { return strcmp(a, other.a) == 0; }
+};
+
+namespace std {
+  template <> struct hash<char_array_s> {
+    std::size_t operator()(const char_array_s &k) const {
+      size_t hash = 0;
+      const char *s = k.a;
+      while (*s) hash = hash * 31421 + (*s++) + 6927;
+      return hash;
+    };
+  };
+}
+
+static void
+test_dict_big(unsigned long  n)
+{
+  flat_hash_map<char_array_s, char_array_s> dict;
+
+  for (size_t i = 0; i < n; i++) {
+    char_array_s s1, s2;
+    sprintf(s1.a, "%u", rand_get());
+    sprintf(s2.a, "%u", rand_get());
+    dict[s1] = s2;
+  }
+  rand_init();
+  unsigned int s = 0;
+  for (size_t i = 0; i < n; i++) {
+    char_array_s s1;
+    sprintf(s1.a, "%u", rand_get());
+    flat_hash_map<char_array_s, char_array_s>::iterator it = dict.find(s1);
+    if (it != dict.end())
+      s ++;
+  }
+  g_result = s;
+}
+
+/********************************************************************************************/
+static void
+test_dict_str(unsigned long  n)
+{
+  flat_hash_map<string, string> dict;
+
+  for (size_t i = 0; i < n; i++) {
+    string s1 = static_cast<ostringstream*>( &(ostringstream() << rand_get()) )->str();
+    string s2 = static_cast<ostringstream*>( &(ostringstream() << rand_get()) )->str();
+    dict[s1] = s2;
+  }
+  rand_init();
+  unsigned int s = 0;
+  for (size_t i = 0; i < n; i++) {
+    string s1 = static_cast<ostringstream*>( &(ostringstream() << rand_get()) )->str();
+    flat_hash_map<string, string>::iterator it = dict.find(s1);
+    if (it != dict.end())
+      s ++;
+  }
+  g_result = s;
+}
+
+/********************************************************************************************/
+
+int main(int argc, const char *argv[])
+{
+  int n = (argc > 1) ? atoi(argv[1]) : 0;
+  if (n == 42)
+    test_function("Dict(u)time", 1000000, test_dict2);
+  if (n == 41)
+    test_function("DictB  time", 1000000, test_dict_big);
+  if (n == 43)
+    test_function("DictS(u)  time", 1000000, test_dict_str);
+  exit(0);
+}