diff --git a/plugins/HDF_IO.hh b/plugins/HDF_IO.hh
index f0cee50..a0e7353 100755
--- a/plugins/HDF_IO.hh
+++ b/plugins/HDF_IO.hh
@@ -44,8 +44,15 @@ hid_t GetDataType( void )
   if( typeid(T) == typeid(double) )
     return H5T_NATIVE_DOUBLE;
   
-	//if( typeid(T) == typeid(long long) )
-	//  return H5T_NATIVE_LLONG;
+	if( typeid(T) == typeid(long long) )
+		return H5T_NATIVE_LLONG;
+	
+	if( typeid(T) == typeid(unsigned long long) )
+		return H5T_NATIVE_ULLONG;
+	
+	if( typeid(T) == typeid(size_t) )
+		return H5T_NATIVE_ULLONG;
+	
   
   std::cerr << " - Error: [HDF_IO] trying to evaluate unsupported type in GetDataType\n\n";
   return -1;
@@ -90,6 +97,8 @@ inline void HDFReadVector( const std::string Filename, const std::string ObjName
 }
 
 
+
+
 inline void HDFGetDatasetExtent( const std::string Filename, const std::string ObjName, std::vector<int> &Extent )
 {
   hid_t HDF_FileID, HDF_DatasetID, HDF_DataspaceID;
@@ -751,6 +760,51 @@ inline void HDFWriteDataset3D( const std::string Filename, const std::string Obj
   H5Fclose( HDF_FileID );
 }
 
+
+template< typename T >
+struct HDFHyperslabWriter3Ds
+{
+	hid_t dset_id_, type_id_, file_id_;
+	
+	HDFHyperslabWriter3Ds( const std::string Filename, const std::string ObjName, size_t nd[3] )
+	{
+		hid_t filespace;
+		
+		hsize_t sizes[4] = { 1, nd[0], nd[1], nd[2] };
+		
+		type_id_	= GetDataType<T>();
+		file_id_	= H5Fopen( Filename.c_str(), H5F_ACC_RDWR, H5P_DEFAULT );
+		filespace	= H5Screate_simple( 4, sizes, NULL );
+		dset_id_	= H5Dcreate( file_id_, ObjName.c_str(), type_id_, filespace, H5P_DEFAULT );
+		
+		H5Sclose(filespace);
+	}
+	
+	~HDFHyperslabWriter3Ds()
+	{
+		H5Dclose( dset_id_ );
+		H5Fclose( file_id_ );
+	}
+	
+	void write_slab( T* data, size_t* count, size_t* offset )
+	{
+		
+		hsize_t counts[4] = { 1, count[0], count[1], count[2] };
+		hsize_t offsets[4] = { 0, offset[0], offset[1], offset[2] };
+		
+		hid_t filespace = H5Dget_space(dset_id_);
+		hid_t memspace  = H5Screate_simple(4, counts, NULL);
+		H5Sselect_hyperslab( filespace, H5S_SELECT_SET, offsets, NULL, counts, NULL );
+		
+		herr_t status;
+		status = H5Dwrite(dset_id_, type_id_, memspace, filespace, H5P_DEFAULT, reinterpret_cast<void*>(data));
+		H5Sclose(filespace);
+		H5Sclose(memspace);
+	}
+	
+};
+
+
 template< typename T >
 inline void HDFWriteDataset3Ds( const std::string Filename, const std::string ObjName, unsigned nd[3], const std::vector< T > &Data )
 {
diff --git a/plugins/output_enzo.cc b/plugins/output_enzo.cc
index 98bd75a..bd716b5 100644
--- a/plugins/output_enzo.cc
+++ b/plugins/output_enzo.cc
@@ -17,13 +17,19 @@
 
 #include "HDF_IO.hh"
 
+//#define MAX_SLAB_SIZE	134217728  // = 128 MBytes
+								   //#define MAX_SLAB_SIZE   33554432   // = 32 Mbytes
+
+#define MAX_SLAB_SIZE   1048576
+
+
 class enzo_output_plugin : public output_plugin
 {
 protected:
 	
 	struct patch_header{
 		int component_rank;
-		int component_size;
+		size_t component_size;
 		std::vector<int> dimensions;
 		int rank;
 		std::vector<int> top_grid_dims;
@@ -88,26 +94,65 @@ protected:
 			
             
 			//... need to copy data because we need to get rid of the ghost zones
-			std::vector<double> data;
-			data.reserve( ng[0]*ng[1]*ng[2] );
+			//... write in slabs if data is more than MAX_SLAB_SIZE (default 128 MB)
 			
-			for( int k=0; k<ng[2]; ++k )
-				for( int j=0; j<ng[1]; ++j )
-					for( int i=0; i<ng[0]; ++i )
-						data.push_back( (add+(*gh.get_grid(ilevel))(i,j,k))*factor );
+			size_t all_data_size = (size_t)ng[0] * (size_t)ng[1] * (size_t)ng[2];
+			size_t max_slab_size = std::min((size_t)MAX_SLAB_SIZE/sizeof(double), all_data_size );
+			size_t slices_in_slab = (size_t)((double)max_slab_size / ((size_t)ng[0] * (size_t)ng[1]));
+			
+			size_t nsz[3] = { ng[2], ng[1], ng[0] };
+				
+			if( levelmin_ != levelmax_ )
+				sprintf( enzoname, "%s.%d", fieldname.c_str(), ilevel-levelmin_ );
+			else
+				sprintf( enzoname, "%s", fieldname.c_str() );
 			
-			sprintf( enzoname, "%s.%d", fieldname.c_str(), ilevel-levelmin_ );
 			sprintf( filename, "%s/%s", fname_.c_str(), enzoname );
 			
 			HDFCreateFile( filename );
 			write_sim_header( filename, the_sim_header );
-			HDFWriteDataset3Ds( filename, enzoname, reinterpret_cast<unsigned*>(&ng_fortran[0]), data );
 			
+			HDFHyperslabWriter3Ds<double> *slab_writer = new HDFHyperslabWriter3Ds<double>( filename, enzoname, nsz );
+			
+			double *data_buf = new double[ slices_in_slab * (size_t)ng[0] * (size_t)ng[1] ];
+			
+			size_t slices_written = 0;
+			while( slices_written < (size_t)ng[2] )
+			{
+				slices_in_slab = std::min( (size_t)ng[2]-slices_written, slices_in_slab );
+				
+				#pragma omp parallel for
+				for( int k=0; k<(int)slices_in_slab; ++k )
+					for( int j=0; j<ng[1]; ++j )
+						for( int i=0; i<ng[0]; ++i )
+							data_buf[ (size_t)(k*ng[1]+j)*(size_t)ng[0]+(size_t)i ] = 
+									(add+(*gh.get_grid(ilevel))(i,j,k+slices_written))*factor;
+				
+				size_t count[3], offset[3];
+				
+				count[0] = slices_in_slab;
+				count[1] = ng[1];
+				count[2] = ng[0];
+				
+				offset[0] = slices_written;;
+				offset[1] = 0;
+				offset[2] = 0;
+				
+				slab_writer->write_slab( data_buf, count, offset );
+				slices_written += slices_in_slab;
+				
+			}
+			
+			delete[] data_buf;
+			
+			delete slab_writer;
+			
+						
 			//... header data for the patch
 			patch_header ph;
 			
 			ph.component_rank	= 1;
-			ph.component_size	= ng[0]*ng[1]*ng[2];
+			ph.component_size	= (size_t)ng[0]*(size_t)ng[1]*(size_t)ng[2];
 			ph.dimensions		= ng;
 			ph.rank				= 3;
 			
@@ -120,7 +165,7 @@ protected:
 			ph.top_grid_start.push_back( (int)(gh.offset_abs(ilevel, 0)*rfac) );
 			ph.top_grid_start.push_back( (int)(gh.offset_abs(ilevel, 1)*rfac) );
 			ph.top_grid_start.push_back( (int)(gh.offset_abs(ilevel, 2)*rfac) );
-			 
+			
 			ph.top_grid_end.push_back( ph.top_grid_start[0] + (int)(ng[0]*rfac) );
 			ph.top_grid_end.push_back( ph.top_grid_start[1] + (int)(ng[1]*rfac) );
 			ph.top_grid_end.push_back( ph.top_grid_start[2] + (int)(ng[2]*rfac) );
@@ -185,7 +230,7 @@ public:
 		
 		sprintf( filename, "%s/parameter_file.txt", fname_.c_str() );
 		
-		std::ofstream ofs( filename, std::ios::trunc );
+		std::ofstream ofs( filename, std::ios::trunc );		
 		
 		ofs
 			<< "#\n"