diff --git a/ompi/mca/io/ompio/io_ompio.c b/ompi/mca/io/ompio/io_ompio.c
index cb5a50a5c1..1b08917de4 100644
--- a/ompi/mca/io/ompio/io_ompio.c
+++ b/ompi/mca/io/ompio/io_ompio.c
@@ -1030,13 +1030,29 @@ int ompi_io_ompio_set_aggregator_props (struct mca_io_ompio_file_t *fh,
     fh->f_flags |= OMPIO_AGGREGATOR_IS_SET;
 
     if (-1 == num_aggregators) {
-        mca_io_ompio_create_groups(fh,bytes_per_proc);
+        if ( SIMPLE == mca_io_ompio_grouping_option ||
+            NO_REFINEMENT == mca_io_ompio_grouping_option ) {
+            fh->f_aggregator_index = 0;
+            fh->f_final_num_aggrs  = fh->f_init_num_aggrs;
+            fh->f_procs_per_group  = fh->f_init_procs_per_group;
+
+            fh->f_procs_in_group = (int*)malloc (fh->f_procs_per_group * sizeof(int));
+            if (NULL == fh->f_procs_in_group) {
+                opal_output (1, "OUT OF MEMORY\n");
+                return OMPI_ERR_OUT_OF_RESOURCE;
+            }
+
+            for (j=0 ; j<fh->f_procs_per_group ; j++) {
+                fh->f_procs_in_group[j] = fh->f_init_procs_in_group[j];
+            }
+        }
+        else {
+            mca_io_ompio_create_groups(fh,bytes_per_proc);
+        }
         return OMPI_SUCCESS;
     }
 
    //Forced number of aggregators
-   else
-   {
     /* calculate the offset at which each group of processes will start */
     procs_per_group = ceil ((float)fh->f_size/num_aggregators);
 
@@ -1062,7 +1078,6 @@ int ompi_io_ompio_set_aggregator_props (struct mca_io_ompio_file_t *fh,
     fh->f_final_num_aggrs  = num_aggregators;
 
     return OMPI_SUCCESS;
-   }
  }
 
 
diff --git a/ompi/mca/io/ompio/io_ompio.h b/ompi/mca/io/ompio/io_ompio.h
index 703ed0bbc8..087765fae1 100644
--- a/ompi/mca/io/ompio/io_ompio.h
+++ b/ompi/mca/io/ompio/io_ompio.h
@@ -101,12 +101,17 @@ OMPI_DECLSPEC extern int mca_io_ompio_coll_timing_info;
 #define OMPIO_MERGE                     1
 #define OMPIO_SPLIT                     2
 #define OMPIO_RETAIN                    3
+
 #define DATA_VOLUME                     1
 #define UNIFORM_DISTRIBUTION            2
-#define OMPIO_UNIFORM_DIST_THRESHOLD  0.5
 #define CONTIGUITY                      3
-#define OMPIO_CONTG_THRESHOLD     1048576
 #define OPTIMIZE_GROUPING               4
+#define SIMPLE                          5
+#define NO_REFINEMENT                   6
+
+
+#define OMPIO_UNIFORM_DIST_THRESHOLD  0.5
+#define OMPIO_CONTG_THRESHOLD     1048576
 #define OMPIO_PROCS_PER_GROUP_TAG       0
 #define OMPIO_PROCS_IN_GROUP_TAG        1
 #define OMPIO_MERGE_THRESHOLD         0.5
diff --git a/ompi/mca/io/ompio/io_ompio_component.c b/ompi/mca/io/ompio/io_ompio_component.c
index 4c2c086821..9007d2f401 100644
--- a/ompi/mca/io/ompio/io_ompio_component.c
+++ b/ompi/mca/io/ompio/io_ompio_component.c
@@ -38,7 +38,7 @@ int mca_io_ompio_record_offset_info = 0;
 int mca_io_ompio_coll_timing_info = 0;
 int mca_io_ompio_sharedfp_lazy_open = 1;
 
-int mca_io_ompio_grouping_option=0;
+int mca_io_ompio_grouping_option=4;
 
 /*
  * Private functions
@@ -202,10 +202,13 @@ static int register_component(void)
                                            MCA_BASE_VAR_SCOPE_READONLY,
                                            &mca_io_ompio_sharedfp_lazy_open);
 
-    mca_io_ompio_grouping_option = 0;
+    mca_io_ompio_grouping_option = 4;
     (void) mca_base_component_var_register(&mca_io_ompio_component.io_version,
                                            "grouping_option",
-                                           "Option for grouping of processes in the aggregator selection",
+                                           "Option for grouping of processes in the aggregator selection "
+                                           "1: Data volume based grouping 2: create uniform groups 3: maximimze "
+                                           "contiguity 4: hybrid optimization (default) 5: simple/no optimization "
+                                           "6: skip refinement step",
                                            MCA_BASE_VAR_TYPE_INT, NULL, 0, 0,
                                            OPAL_INFO_LVL_9,
                                            MCA_BASE_VAR_SCOPE_READONLY,