diff --git a/Code/Mantid/Framework/API/src/MemoryManager.cpp b/Code/Mantid/Framework/API/src/MemoryManager.cpp
index 8b62729a25da5b99add876729636560104534893..3bff35cc798f4477ddfc2c775e1601294d400c1e 100644
--- a/Code/Mantid/Framework/API/src/MemoryManager.cpp
+++ b/Code/Mantid/Framework/API/src/MemoryManager.cpp
@@ -5,7 +5,9 @@
 #include "MantidKernel/ConfigService.h"
 #include "MantidKernel/Memory.h"
 
-//#include "/home/8oz/Code/google-perftools/src/google/malloc_extension.h"
+#ifdef USE_TCMALLOC
+#include "google/malloc_extension.h"
+#endif
 
 // Get the 'meat' of this class from the appropriate file for the platform
 #ifdef __linux__
@@ -143,15 +145,17 @@ bool MemoryManagerImpl::goForManagedWorkspace(int NVectors, int XLength, int YLe
 void MemoryManagerImpl::releaseFreeMemory()
 {
 
-//    Kernel::MemoryStats mem;
-//    mem.update();
-//    std::cout << "Before releasing: \n" << mem << "\n";
-//
-//    // Make TCMALLOC release memory to the system
-//    MallocExtension::instance()->ReleaseFreeMemory();
-//
-//    mem.update();
-//    std::cout << "After releasing: \n" << mem << "\n";
+#ifdef USE_TCMALLOC
+    Kernel::MemoryStats mem;
+    mem.update();
+    std::cout << "Before releasing: " << mem << "\n";
+
+    // Make TCMALLOC release memory to the system
+    MallocExtension::instance()->ReleaseFreeMemory();
+
+    mem.update();
+    std::cout << "After releasing:  " << mem << "\n";
+#endif
 }
 
 } // namespace API
diff --git a/Code/Mantid/Framework/CMakeLists.txt b/Code/Mantid/Framework/CMakeLists.txt
index c6f62086c85db59ce2824d907c329207ebaff999..b49be50d60716f36d7c20feea0c9e9b6a909f3d9 100644
--- a/Code/Mantid/Framework/CMakeLists.txt
+++ b/Code/Mantid/Framework/CMakeLists.txt
@@ -47,6 +47,8 @@ find_package ( Tcmalloc )
 # If not found, or not wanted, just carry on without it
 if ( USE_TCMALLOC AND TCMALLOC_FOUND )
   set ( TCMALLOC_LIBRARY ${TCMALLOC_LIBRARIES} )
+  # Make a C++ define to use as flags in, e.g. MemoryManager.cpp
+  add_definitions ( -DUSE_TCMALLOC )
 endif ()
 
 # Might just as well link everything to Boost & Poco (found in CommonSetup)
diff --git a/Code/Mantid/Framework/Kernel/src/Memory.cpp b/Code/Mantid/Framework/Kernel/src/Memory.cpp
index 65156ec3a0b57b616528bec8cc2129b74e44b7c0..e528eb15f52209a3c4f7dd178df3de7b3c1220ed 100644
--- a/Code/Mantid/Framework/Kernel/src/Memory.cpp
+++ b/Code/Mantid/Framework/Kernel/src/Memory.cpp
@@ -30,7 +30,7 @@ string memToString(const TYPE mem_in_kiB)
   std::stringstream buffer;
   if (mem_in_kiB < static_cast<TYPE>(1024))
     buffer << mem_in_kiB << "kiB";
-  else if (mem_in_kiB < static_cast<TYPE>(1024 * 1024))
+  else if (mem_in_kiB < static_cast<TYPE>(100 * 1024 * 1024))
     buffer << (mem_in_kiB/static_cast<TYPE>(1024)) << "MiB";
   else
     buffer << (mem_in_kiB/static_cast<TYPE>(1024*1024)) << "GiB";