diff --git a/Eigen/src/Sparse/RandomSetter.h b/Eigen/src/Sparse/RandomSetter.h
index efe8ba2db..8606e03c6 100644
--- a/Eigen/src/Sparse/RandomSetter.h
+++ b/Eigen/src/Sparse/RandomSetter.h
@@ -90,12 +90,12 @@ class RandomSetter
     inline RandomSetter(SparseMatrixType& target)
       : mp_target(&target)
     {
-      int outerPackets = target.outerSize() >> OuterPacketBits;
+      m_outerPackets = target.outerSize() >> OuterPacketBits;
       if (target.outerSize()&OuterPacketMask)
-        outerPackets += 1;
-      m_hashmaps = new HashMapType[outerPackets];
+        m_outerPackets += 1;
+      m_hashmaps = new HashMapType[m_outerPackets];
       KeyType ik = (1<<OuterPacketBits)*mp_target->innerSize()+1;
-      for (int k=0; k<outerPackets; ++k)
+      for (int k=0; k<m_outerPackets; ++k)
         HashMapTraits<ScalarWrapper>::setInvalidKey(m_hashmaps[k],ik);
     }
 
@@ -115,11 +115,20 @@ class RandomSetter
       return m_hashmaps[outerMajor][key].value;
     }
 
+    int nonZeros() const
+    {
+      int nz = 0;
+      for (int k=0; k<m_outerPackets; ++k)
+        nz += m_hashmaps[k].size();
+      return nz;
+    }
+
 
   protected:
 
     HashMapType* m_hashmaps;
     SparseMatrixType* mp_target;
+    int m_outerPackets;
 };
 
 #endif // EIGEN_RANDOMSETTER_H
diff --git a/bench/sparse_randomsetter.cpp b/bench/sparse_randomsetter.cpp
new file mode 100644
index 000000000..7868e177a
--- /dev/null
+++ b/bench/sparse_randomsetter.cpp
@@ -0,0 +1,104 @@
+
+#define NOGMM
+#define NOMTL
+
+#include <map>
+#include <ext/hash_map>
+#include <google/dense_hash_map>
+#include <google/sparse_hash_map>
+
+#ifndef SIZE
+#define SIZE 10000
+#endif
+
+#ifndef DENSITY
+#define DENSITY 0.01
+#endif
+
+#ifndef REPEAT
+#define REPEAT 1
+#endif
+
+#include "BenchSparseUtil.h"
+
+#ifndef MINDENSITY
+#define MINDENSITY 0.0004
+#endif
+
+#ifndef NBTRIES
+#define NBTRIES 10
+#endif
+
+#define BENCH(X) \
+  timer.reset(); \
+  for (int _j=0; _j<NBTRIES; ++_j) { \
+    timer.start(); \
+    for (int _k=0; _k<REPEAT; ++_k) { \
+        X  \
+  } timer.stop(); }
+
+int main(int argc, char *argv[])
+{
+  int rows = SIZE;
+  int cols = SIZE;
+  float density = DENSITY;
+
+  EigenSparseMatrix sm1(rows,cols), sm2(rows,cols);
+
+
+  int n = rows*cols*density;
+  std::cout << "n = " << n << "\n";
+  int dummy;
+  BenchTimer t;
+
+  t.reset(); t.start();
+  for (int k=0; k<n; ++k)
+    dummy = ei_random<int>(0,rows-1) + ei_random<int>(0,cols-1);
+  t.stop();
+  double rtime = t.value();
+  std::cout << "rtime = " << rtime << " (" << dummy << ")\n\n";
+  const int Bits = 6;
+  for (;;)
+  {
+    {
+      RandomSetter<EigenSparseMatrix,StdMapTraits,Bits> set1(sm1);
+      t.reset(); t.start();
+      for (int k=0; k<n; ++k)
+        set1(ei_random<int>(0,rows-1),ei_random<int>(0,cols-1)) += 1;
+      t.stop();
+      std::cout << "std::map =>      \t" << t.value()-rtime
+                << " nnz=" << set1.nonZeros() << "\n";getchar();
+    }
+    {
+      RandomSetter<EigenSparseMatrix,GnuHashMapTraits,Bits> set1(sm1);
+      t.reset(); t.start();
+      for (int k=0; k<n; ++k)
+        set1(ei_random<int>(0,rows-1),ei_random<int>(0,cols-1)) += 1;
+      t.stop();
+      std::cout << "gnu::hash_map => \t" << t.value()-rtime
+                << " nnz=" << set1.nonZeros() << "\n";getchar();
+    }
+    {
+      RandomSetter<EigenSparseMatrix,GoogleDenseHashMapTraits,Bits> set1(sm1);
+      t.reset(); t.start();
+      for (int k=0; k<n; ++k)
+        set1(ei_random<int>(0,rows-1),ei_random<int>(0,cols-1)) += 1;
+      t.stop();
+      std::cout << "google::dense => \t" << t.value()-rtime
+                << " nnz=" << set1.nonZeros() << "\n";getchar();
+    }
+    {
+      RandomSetter<EigenSparseMatrix,GoogleSparseHashMapTraits,Bits> set1(sm1);
+      t.reset(); t.start();
+      for (int k=0; k<n; ++k)
+        set1(ei_random<int>(0,rows-1),ei_random<int>(0,cols-1)) += 1;
+      t.stop();
+      std::cout << "google::sparse => \t" << t.value()-rtime
+                << " nnz=" << set1.nonZeros() << "\n";getchar();
+    }
+    std::cout << "\n\n";
+  }
+
+  return 0;
+}
+