diff --git a/src/include/array/array_base.h b/src/include/array/array_base.h
index 97e48a7..bf529d5 100644
--- a/src/include/array/array_base.h
+++ b/src/include/array/array_base.h
@@ -149,6 +149,19 @@ namespace CNORXZ
 	/** check if container views the data, i.e. it does not own it */
 	virtual bool isView() const = 0;
 
+	/** Perform compatibility checks
+	    @tparam Acc index type or index pack type
+	    @param acc index or index pack.
+	 */
+	template <class Acc>
+	void checkFormatCompatibility(const Acc& acc) const;
+
+	/** check if format is trivial
+	    @return true if container is data owning array, else return
+	    result of the corresponding container index
+	 */
+	virtual bool formatIsTrivial() const = 0;
+
     protected:
 	RangePtr mRange; /**< the container range */
 
@@ -171,18 +184,6 @@ namespace CNORXZ
 	template <class Acc>
 	const_iterator itLexSave(const Acc& acc) const;
 
-	/** Perform compatibility checks
-	    @tparam Acc index type or index pack type
-	    @param acc index or index pack.
-	 */
-	template <class Acc>
-	void checkFormatCompatibility(const Acc& acc) const;
-
-	/** check if format is trivial
-	    @return true if container is data owning array, else return
-	    result of the corresponding container index
-	 */
-	virtual bool formatIsTrivial() const = 0;
     };
 
     /** ****
diff --git a/src/opt/mpi/include/rarray.cc.h b/src/opt/mpi/include/rarray.cc.h
index 9d67dee..3d84b5a 100644
--- a/src/opt/mpi/include/rarray.cc.h
+++ b/src/opt/mpi/include/rarray.cc.h
@@ -221,14 +221,13 @@ namespace CNORXZ
 	}
 
 	template <typename T>
-	template <class Index1, class Index2>
-	void RCArray<T>::load(const Sptr<Index1>& lpi, const Sptr<Index2>& ai,
-			      const Sptr<Vector<SizeT>>& imap) const
+	template <class TarI, class RTarI, class SrcI, class RSrcI, class I>
+	void RCArray<T>::load(const Sptr<RIndex<TarI,RTarI>>& lpi, const Sptr<RIndex<SrcI,RSrcI>>& ai,
+			      const Sptr<I>& i, const Sptr<Vector<SizeT>>& imap) const
 	{
-	    // TODO: blocks!!!
-	    const SizeT blocks = 0; assert(0); // TODO!!!
-	    
-	    setupBuffer(ai, lpi, imap, *mA, mBuf, mMap, blocks);
+	    mA->checkFormatCompatibility(ai->local()*i);
+	    const SizeT blocks = i->pmax().val();
+	    setupBuffer(lpi, ai, imap, *mA, mBuf, mMap, blocks);
 	}
 
 	template <typename T>
@@ -242,7 +241,7 @@ namespace CNORXZ
 	}
 
 	template <class TarI, class RTarI, class SrcI, class RSrcI, typename T>
-	void setupBuffer(const Sptr<RIndex<TarI,RTarI>>& rgj, const Sptr<RIndex<SrcI,RSrcI>>& rgi,
+	void setupBuffer(const Sptr<RIndex<TarI,RTarI>>& rgi, const Sptr<RIndex<SrcI,RSrcI>>& rgj,
 			 const Sptr<Vector<SizeT>>& imap, const CArrayBase<T>& data,
 			 Vector<T>& buf, Vector<const T*>& map, const SizeT blocks)
 	{
diff --git a/src/opt/mpi/include/rarray.h b/src/opt/mpi/include/rarray.h
index 3766e0e..c0414d0 100644
--- a/src/opt/mpi/include/rarray.h
+++ b/src/opt/mpi/include/rarray.h
@@ -117,15 +117,16 @@ namespace CNORXZ
 	     */
 	    const Vector<const T*> buffermap() const;
 	    
-	    /** Load all data from other ranks that is accessed by i2 in a loop over i1.
-		imap indicates the position of i2 for a given position of i1.
-		@param lpi Loop index.
-		@param ai Access index.
+	    /** Load all data from other ranks that is accessed by ai in a loop over lpi.
+		imap indicates the global (!) position of ai for a given (local) position of lpi.
+		@param lpi Loop rank index.
+		@param ai Access rank index.
+		@param i Index for non-ranked dimensions.
 		@param imap Index position map.
 	     */
-	    template <class Index1, class Index2>
-	    void load(const Sptr<Index1>& lpi, const Sptr<Index2>& ai,
-		      const Sptr<Vector<SizeT>>& imap) const;
+	    template <class TarI, class RTarI, class SrcI, class RSrcI, class I>
+	    void load(const Sptr<RIndex<TarI,RTarI>>& lpi, const Sptr<RIndex<SrcI,RSrcI>>& ai,
+		      const Sptr<I>& i, const Sptr<Vector<SizeT>>& imap) const;
 
 	    /** Load all data from other ranks that is accessed by f(i).
 		@param lpi Loop index.