*** .mpich/src/coll/coll.h	Mon Jul 24 21:44:51 1995
--- coll.h	Tue Aug 29 11:00:34 1995
***************
*** 1,5 ****
! /* 	$Id: coll.h,v 1.7 1995/07/25 02:44:51 gropp Exp $	 */
  
  
  /*
  
--- 1,5 ----
! /* 	$Id: coll.h,v 1.7 1995/07/25 02:44:51 gropp Exp gropp $	 */
  
  
  /*
  
***************
*** 42,54 ****
     Block sizes for various collective operations
     
     For most systems, a size of 1 is optimal.  The claim has been made that
     for the SP1, 3 is better.
   */
  #if defined(MPI_rs6000)
! #define MPIR_BCAST_BLOCK_SIZE 3
  #else
  #define MPIR_BCAST_BLOCK_SIZE 1
  #endif
  
  /* Tags for point to point operations which implement collective operations */
  #define MPIR_BARRIER_TAG               1
--- 42,61 ----
     Block sizes for various collective operations
     
     For most systems, a size of 1 is optimal.  The claim has been made that
     for the SP1, 3 is better.
+    
+    NOTE THAT THIS MUST BE DISABLED FOR HETEROGENEOUS SYSTEMS
   */
+ #if defined(MPID_HAS_HETERO)
+ #define MPIR_BCAST_BLOCK_SIZE 1
+ #else
  #if defined(MPI_rs6000)
! /* #define MPIR_BCAST_BLOCK_SIZE 3 */
! #define MPIR_BCAST_BLOCK_SIZE 1
  #else
  #define MPIR_BCAST_BLOCK_SIZE 1
+ #endif
  #endif
  
  /* Tags for point to point operations which implement collective operations */
  #define MPIR_BARRIER_TAG               1