diff --git a/apps/tests/CMakeLists.txt b/apps/tests/CMakeLists.txt
index 33363eb3b..e4ad98cdc 100644
--- a/apps/tests/CMakeLists.txt
+++ b/apps/tests/CMakeLists.txt
@@ -4,7 +4,8 @@ test_mpi_grid;test_enu;test_eigen;test_gemm;test_wf_inner;test_memop;test_gvec_s
 test_mem_pool;test_mem_alloc;test_examples;test_mpi_p2p_cyclic;test_pw_sph_exp;test_mpi_p2p;\
 test_wf_ortho;test_mixer;test_davidson;test_lapw_xc;test_phase;test_fp;test_pppw_xc;\
 test_atomic_orbital_index;test_sym;test_blacs;test_reduce;test_mpi_comm_split;test_wf_trans;\
-test_wf_fft;test_potrf;test_lr_solver;test_radial_solver;test_radial_dirac;test_radial_schroed;test_iter_gvec")
+test_wf_fft;test_potrf;test_lr_solver;test_radial_solver;test_radial_dirac;test_radial_schroed;test_iter_gvec;\
+test_max_mem")
 
 foreach(_test ${_tests})
   add_executable(${_test} ${_test}.cpp)
diff --git a/apps/tests/test_gemm.cpp b/apps/tests/test_gemm.cpp
index 99ee19533..0b5b75337 100644
--- a/apps/tests/test_gemm.cpp
+++ b/apps/tests/test_gemm.cpp
@@ -54,7 +54,8 @@ test_gemm_impl(int M, int N, int K, int transa, la::lib_t la__, memory_t memA__,
 
     c.zero(memC__);
     if (!is_host_memory(memC__)) {
-        c.allocate(memory_t::host);
+        c.allocate(memory_t::host_pinned);
+        c.zero();
     }
 
     char TA[] = {'N', 'T', 'C'};
diff --git a/apps/tests/test_hloc.cpp b/apps/tests/test_hloc.cpp
index c6ab17156..7a7562ac8 100644
--- a/apps/tests/test_hloc.cpp
+++ b/apps/tests/test_hloc.cpp
@@ -32,14 +32,15 @@ test_hloc_impl(sirius::Simulation_context& ctx__, int num_bands__, int use_gpu__
 
     sirius::Local_operator<T> hloc(ctx__, fft, gvec_fft);
 
-    wf::Wave_functions<T> phi(gvec, wf::num_mag_dims(0), wf::num_bands(4 * num_bands__), memory_t::host);
+    wf::Wave_functions<T> phi(gvec, wf::num_mag_dims(0), wf::num_bands(4 * num_bands__), memory_t::host_pinned);
+    #pragma omp patallel for
     for (int i = 0; i < 4 * num_bands__; i++) {
         for (int j = 0; j < phi.ld(); j++) {
             phi.pw_coeffs(j, wf::spin_index(0), wf::band_index(i)) = random<std::complex<T>>();
         }
         phi.pw_coeffs(0, wf::spin_index(0), wf::band_index(i)) = 1.0;
     }
-    wf::Wave_functions<T> hphi(gvec, wf::num_mag_dims(0), wf::num_bands(4 * num_bands__), memory_t::host);
+    wf::Wave_functions<T> hphi(gvec, wf::num_mag_dims(0), wf::num_bands(4 * num_bands__), memory_t::host_pinned);
 
     {
         auto mem_phi         = (use_gpu__) ? memory_t::device : memory_t::host;
@@ -59,6 +60,7 @@ test_hloc_impl(sirius::Simulation_context& ctx__, int num_bands__, int use_gpu__
     }
 
     double diff{0};
+    #pragma omp parallel for reduction(+:diff)
     for (int i = 0; i < 4 * num_bands__; i++) {
         for (int j = 0; j < phi.ld(); j++) {
             int ig  = gvec->offset() + j;
@@ -69,6 +71,7 @@ test_hloc_impl(sirius::Simulation_context& ctx__, int num_bands__, int use_gpu__
                              2);
         }
     }
+
     if (diff != diff) {
         RTE_THROW("NaN");
     }
diff --git a/apps/tests/test_max_mem.cpp b/apps/tests/test_max_mem.cpp
new file mode 100644
index 000000000..c5bc9f645
--- /dev/null
+++ b/apps/tests/test_max_mem.cpp
@@ -0,0 +1,49 @@
+/* This file is part of SIRIUS electronic structure library.
+ *
+ * Copyright (c), ETH Zurich.  All rights reserved.
+ *
+ * Please, refer to the LICENSE file in the root directory.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <sirius.hpp>
+#include "testing.hpp"
+
+using namespace sirius;
+
+int
+test_max_mem(cmd_args const& args)
+{
+    std::cout << "Free avaialble memory : " << (get_available_memory() >> 30) << " Gb" << std::endl;
+    auto M = get_memory_t(args.value<std::string>("memory_t", "host"));
+    size_t size = args.value<int>("size", 1);
+
+    //std::cout << "attempting to allocate " << size << " Gb" << std::endl;
+    //size *= (1 << 30);
+    //mdarray<char, 1> a({size}, M);
+    //a.zero(M);
+
+    std::vector<mdarray<char, 1>> v;
+    for (int i = 0; i < 100; i++) {
+        std::cout << "step : " << i << std::endl;
+        std::cout << "attempting to allocate " << size << " Gb" << std::endl;
+        v.push_back(mdarray<char, 1>({size * (1 << 30)}, M));
+        v.back().zero(M);
+        print_memory_usage(std::cout);
+        std::cout << std::flush;
+    }
+
+    return 0;
+}
+
+int
+main(int argn, char** argv)
+{
+    cmd_args args(argn, argv,
+                  {{"memory_t=", "{string} type of the memory"}, {"size=", "{int} size of array in Gb"}});
+
+    sirius::initialize(1);
+    int result = call_test("test_max_mem", test_max_mem, args);
+    sirius::finalize();
+    return result;
+}