diff --git a/openmp/runtime/src/i18n/en_US.txt b/openmp/runtime/src/i18n/en_US.txt
--- a/openmp/runtime/src/i18n/en_US.txt
+++ b/openmp/runtime/src/i18n/en_US.txt
@@ -469,6 +469,8 @@
 AffHWSubsetEqvLayers         "KMP_HW_SUBSET ignored: %1$s, %2$s: layers are equivalent, please only specify one."
 AffHWSubsetOutOfOrder        "KMP_HW_SUBSET ignored: %1$s layer should come after %2$s."
 AffEqualTopologyTypes        "%1$s: topology layer \"%2$s\" is equivalent to \"%3$s\"."
+AffGranTooCoarseProcGroup    "%1$s: granularity=%2$s is too coarse, setting granularity=group."
+StgDeprecatedValue           "%1$s: \"%2$s\" value is deprecated. Please use \"%3$s\" instead."
 
 # --------------------------------------------------------------------------------------------------
 -*- HINTS -*-
diff --git a/openmp/runtime/src/kmp_affinity.h b/openmp/runtime/src/kmp_affinity.h
--- a/openmp/runtime/src/kmp_affinity.h
+++ b/openmp/runtime/src/kmp_affinity.h
@@ -638,7 +638,9 @@
 
   int depth;
 
-  // The following arrays are all 'depth' long
+  // The following arrays are all 'depth' long and have been
+  // allocated to hold up to KMP_HW_LAST number of objects if
+  // needed so layers can be added without reallocation of any array
 
   // Orderd array of the types in the topology
   kmp_hw_t *types;
@@ -671,6 +673,14 @@
   // Flags describing the topology
   flags_t flags;
 
+  // Insert a new topology layer after allocation
+  void _insert_layer(kmp_hw_t type, const int *ids);
+
+#if KMP_GROUP_AFFINITY
+  // Insert topology information about Windows Processor groups
+  void _insert_windows_proc_groups();
+#endif
+
   // Count each item & get the num x's per y
   // e.g., get the number of cores and the number of threads per core
   // for each (x, y) in (KMP_HW_* , KMP_HW_*)
diff --git a/openmp/runtime/src/kmp_affinity.cpp b/openmp/runtime/src/kmp_affinity.cpp
--- a/openmp/runtime/src/kmp_affinity.cpp
+++ b/openmp/runtime/src/kmp_affinity.cpp
@@ -198,14 +198,82 @@
 ////////////////////////////////////////////////////////////////////////////////
 // kmp_topology_t methods
 
+// Add a layer to the topology based on the ids. Assume the topology
+// is perfectly nested (i.e., so no object has more than one parent)
+void kmp_topology_t::_insert_layer(kmp_hw_t type, const int *ids) {
+  // Figure out where the layer should go by comparing the ids of the current
+  // layers with the new ids
+  int target_layer;
+  int previous_id = kmp_hw_thread_t::UNKNOWN_ID;
+  int previous_new_id = kmp_hw_thread_t::UNKNOWN_ID;
+
+  // Start from the highest layer and work down to find target layer
+  // If new layer is equal to another layer then put the new layer above
+  for (target_layer = 0; target_layer < depth; ++target_layer) {
+    bool layers_equal = true;
+    bool strictly_above_target_layer = false;
+    for (int i = 0; i < num_hw_threads; ++i) {
+      int id = hw_threads[i].ids[target_layer];
+      int new_id = ids[i];
+      if (id != previous_id && new_id == previous_new_id) {
+        // Found the layer we are strictly above
+        strictly_above_target_layer = true;
+        layers_equal = false;
+        break;
+      } else if (id == previous_id && new_id != previous_new_id) {
+        // Found a layer we are below. Move to next layer and check.
+        layers_equal = false;
+        break;
+      }
+      previous_id = id;
+      previous_new_id = new_id;
+    }
+    if (strictly_above_target_layer || layers_equal)
+      break;
+  }
+
+  // Found the layer we are above. Now move everything to accommodate the new
+  // layer. And put the new ids and type into the topology.
+  for (int i = depth - 1, j = depth; i >= target_layer; --i, --j)
+    types[j] = types[i];
+  types[target_layer] = type;
+  for (int k = 0; k < num_hw_threads; ++k) {
+    for (int i = depth - 1, j = depth; i >= target_layer; --i, --j)
+      hw_threads[k].ids[j] = hw_threads[k].ids[i];
+    hw_threads[k].ids[target_layer] = ids[k];
+  }
+  equivalent[type] = type;
+  depth++;
+}
+
+#if KMP_GROUP_AFFINITY
+// Insert the Windows Processor Group structure into the topology
+void kmp_topology_t::_insert_windows_proc_groups() {
+  // Do not insert the processor group structure for a single group
+  if (__kmp_num_proc_groups == 1)
+    return;
+  kmp_affin_mask_t *mask;
+  int *ids = (int *)__kmp_allocate(sizeof(int) * num_hw_threads);
+  KMP_CPU_ALLOC(mask);
+  for (int i = 0; i < num_hw_threads; ++i) {
+    KMP_CPU_ZERO(mask);
+    KMP_CPU_SET(hw_threads[i].os_id, mask);
+    ids[i] = __kmp_get_proc_group(mask);
+  }
+  KMP_CPU_FREE(mask);
+  _insert_layer(KMP_HW_PROC_GROUP, ids);
+  __kmp_free(ids);
+}
+#endif
+
 // Remove layers that don't add information to the topology.
 // This is done by having the layer take on the id = UNKNOWN_ID (-1)
 void kmp_topology_t::_remove_radix1_layers() {
   int preference[KMP_HW_LAST];
   int top_index1, top_index2;
   // Set up preference associative array
-  preference[KMP_HW_PROC_GROUP] = 110;
-  preference[KMP_HW_SOCKET] = 100;
+  preference[KMP_HW_SOCKET] = 110;
+  preference[KMP_HW_PROC_GROUP] = 100;
   preference[KMP_HW_CORE] = 95;
   preference[KMP_HW_THREAD] = 90;
   preference[KMP_HW_NUMA] = 85;
@@ -440,7 +508,7 @@
   kmp_topology_t *retval;
   // Allocate all data in one large allocation
   size_t size = sizeof(kmp_topology_t) + sizeof(kmp_hw_thread_t) * nproc +
-                sizeof(int) * ndepth * 3;
+                sizeof(int) * (size_t)KMP_HW_LAST * 3;
   char *bytes = (char *)__kmp_allocate(size);
   retval = (kmp_topology_t *)bytes;
   if (nproc > 0) {
@@ -453,8 +521,8 @@
   int *arr =
       (int *)(bytes + sizeof(kmp_topology_t) + sizeof(kmp_hw_thread_t) * nproc);
   retval->types = (kmp_hw_t *)arr;
-  retval->ratio = arr + ndepth;
-  retval->count = arr + 2 * ndepth;
+  retval->ratio = arr + (size_t)KMP_HW_LAST;
+  retval->count = arr + 2 * (size_t)KMP_HW_LAST;
   KMP_FOREACH_HW_TYPE(type) { retval->equivalent[type] = KMP_HW_UNKNOWN; }
   for (int i = 0; i < ndepth; ++i) {
     retval->types[i] = types[i];
@@ -651,6 +719,9 @@
 }
 
 void kmp_topology_t::canonicalize() {
+#if KMP_GROUP_AFFINITY
+  _insert_windows_proc_groups();
+#endif
   _remove_radix1_layers();
   _gather_enumeration_information();
   _discover_uniformity();
@@ -699,6 +770,25 @@
                   __kmp_hw_get_catalog_string(gran_type));
       __kmp_affinity_gran = gran_type;
     }
+#if KMP_GROUP_AFFINITY
+    // If more than one processor group exists, and the level of
+    // granularity specified by the user is too coarse, then the
+    // granularity must be adjusted "down" to processor group affinity
+    // because threads can only exist within one processor group.
+    // For example, if a user sets granularity=socket and there are two
+    // processor groups that cover a socket, then the runtime must
+    // restrict the granularity down to the processor group level.
+    if (__kmp_num_proc_groups > 1) {
+      int gran_depth = __kmp_topology->get_level(gran_type);
+      int proc_group_depth = __kmp_topology->get_level(KMP_HW_PROC_GROUP);
+      if (gran_depth >= 0 && proc_group_depth >= 0 &&
+          gran_depth < proc_group_depth) {
+        KMP_WARNING(AffGranTooCoarseProcGroup, "KMP_AFFINITY",
+                    __kmp_hw_get_catalog_string(__kmp_affinity_gran));
+        __kmp_affinity_gran = gran_type = KMP_HW_PROC_GROUP;
+      }
+    }
+#endif
     __kmp_affinity_gran_levels = 0;
     for (int i = depth - 1; i >= 0 && get_type(i) != gran_type; --i)
       __kmp_affinity_gran_levels++;
diff --git a/openmp/runtime/src/kmp_settings.cpp b/openmp/runtime/src/kmp_settings.cpp
--- a/openmp/runtime/src/kmp_settings.cpp
+++ b/openmp/runtime/src/kmp_settings.cpp
@@ -3136,6 +3136,7 @@
   }
 #if KMP_GROUP_AFFINITY
   else if (__kmp_str_match("group", 1, value)) {
+    KMP_WARNING(StgDeprecatedValue, name, value, "all");
     __kmp_affinity_top_method = affinity_top_method_group;
   }
 #endif /* KMP_GROUP_AFFINITY */
@@ -6029,65 +6030,27 @@
       // Handle the Win 64 group affinity stuff if there are multiple
       // processor groups, or if the user requested it, and OMP 4.0
       // affinity is not in effect.
-      if (((__kmp_num_proc_groups > 1) &&
-           (__kmp_affinity_type == affinity_default) &&
-           (__kmp_nested_proc_bind.bind_types[0] == proc_bind_default)) ||
-          (__kmp_affinity_top_method == affinity_top_method_group)) {
+      if (__kmp_num_proc_groups > 1 &&
+          __kmp_affinity_type == affinity_default &&
+          __kmp_nested_proc_bind.bind_types[0] == proc_bind_default) {
+        // Do not respect the initial processor affinity mask if it is assigned
+        // exactly one Windows Processor Group since this is interpreted as the
+        // default OS assignment. Not respecting the mask allows the runtime to
+        // use all the logical processors in all groups.
         if (__kmp_affinity_respect_mask == affinity_respect_mask_default &&
             exactly_one_group) {
           __kmp_affinity_respect_mask = FALSE;
         }
+        // Use compact affinity with anticipation of pinning to at least the
+        // group granularity since threads can only be bound to one group.
         if (__kmp_affinity_type == affinity_default) {
           __kmp_affinity_type = affinity_compact;
           __kmp_nested_proc_bind.bind_types[0] = proc_bind_intel;
         }
-        if (__kmp_affinity_top_method == affinity_top_method_default) {
-          if (__kmp_affinity_gran == KMP_HW_UNKNOWN) {
-            __kmp_affinity_top_method = affinity_top_method_group;
-            __kmp_affinity_gran = KMP_HW_PROC_GROUP;
-          } else if (__kmp_affinity_gran == KMP_HW_PROC_GROUP) {
-            __kmp_affinity_top_method = affinity_top_method_group;
-          } else {
-            __kmp_affinity_top_method = affinity_top_method_all;
-          }
-        } else if (__kmp_affinity_top_method == affinity_top_method_group) {
-          if (__kmp_affinity_gran == KMP_HW_UNKNOWN) {
-            __kmp_affinity_gran = KMP_HW_PROC_GROUP;
-          } else if ((__kmp_affinity_gran != KMP_HW_PROC_GROUP) &&
-                     (__kmp_affinity_gran != KMP_HW_THREAD)) {
-            const char *str = __kmp_hw_get_keyword(__kmp_affinity_gran);
-            KMP_WARNING(AffGranTopGroup, var, str);
-            __kmp_affinity_gran = KMP_HW_THREAD;
-          }
-        } else {
-          if (__kmp_affinity_gran == KMP_HW_UNKNOWN) {
-            __kmp_affinity_gran = KMP_HW_CORE;
-          } else if (__kmp_affinity_gran == KMP_HW_PROC_GROUP) {
-            const char *str = NULL;
-            switch (__kmp_affinity_type) {
-            case affinity_physical:
-              str = "physical";
-              break;
-            case affinity_logical:
-              str = "logical";
-              break;
-            case affinity_compact:
-              str = "compact";
-              break;
-            case affinity_scatter:
-              str = "scatter";
-              break;
-            case affinity_explicit:
-              str = "explicit";
-              break;
-            // No MIC on windows, so no affinity_balanced case
-            default:
-              KMP_DEBUG_ASSERT(0);
-            }
-            KMP_WARNING(AffGranGroupType, var, str);
-            __kmp_affinity_gran = KMP_HW_CORE;
-          }
-        }
+        if (__kmp_affinity_top_method == affinity_top_method_default)
+          __kmp_affinity_top_method = affinity_top_method_all;
+        if (__kmp_affinity_gran == KMP_HW_UNKNOWN)
+          __kmp_affinity_gran = KMP_HW_PROC_GROUP;
       } else
 
 #endif /* KMP_GROUP_AFFINITY */