     Test<CUB, unsigned int, NullType, false> (num_items, RANDOM, entropy_reduction, 0, g_bits, CUB_TYPE_STRING(unsigned int));
     Test<THRUST, unsigned int, NullType, false> (num_items, RANDOM, entropy_reduction, 0, g_bits, CUB_TYPE_STRING(unsigned int));
 
+    // Compare CUB and thrust on 64b keys-only
+    Test<CUB, unsigned long long, NullType, false> (num_items, RANDOM, entropy_reduction, 0, g_bits, CUB_TYPE_STRING(unsigned long long));
+    Test<THRUST, unsigned long long, NullType, false> (num_items, RANDOM, entropy_reduction, 0, g_bits, CUB_TYPE_STRING(unsigned long long));
+
+
     // Compare CUB and thrust on 32b key-value pairs
     Test<CUB, unsigned int, unsigned int, false> (num_items, RANDOM, entropy_reduction, 0, g_bits, CUB_TYPE_STRING(unsigned int));
     Test<THRUST, unsigned int, unsigned int, false> (num_items, RANDOM, entropy_reduction, 0, g_bits, CUB_TYPE_STRING(unsigned int));
 
+    // Compare CUB and thrust on 64b key-value pairs
+    Test<CUB, unsigned long long, unsigned long long, false> (num_items, RANDOM, entropy_reduction, 0, g_bits, CUB_TYPE_STRING(unsigned long long));
+    Test<THRUST, unsigned long long, unsigned long long, false> (num_items, RANDOM, entropy_reduction, 0, g_bits, CUB_TYPE_STRING(unsigned long long));
+
 #else
 
     // Compile/run thorough tests

    std::stable_sort(h_pairs, h_pairs + num_items);
    if (DESCENDING) std::reverse(h_pairs, h_pairs + num_items);

    for (int i = 0; i < num_items; ++i)
    {
        h_reference_keys[i]     = h_pairs[i].key;

        if (h_reference_values != NULL)
            h_reference_values[i]   = h_pairs[i].value;
    }

    delete[] h_pairs;


    // Allocate host arrays
    Key     *h_keys             = new Key[num_items];
    Value   *h_values           = (KEYS_ONLY) ? NULL : new Value[num_items];

    Key     *h_reference_keys;
    Value   *h_reference_values;

    // Initialize problem and solution on host
    Initialize<DESCENDING>(
        gen_mode,
        h_keys,
        h_values,
        &h_reference_keys,
        &h_reference_values,
        num_items,
        entropy_reduction,
        begin_bit,
