diff --git a/infer/src/cost/costModels.ml b/infer/src/cost/costModels.ml
index f269621af..8c4b17224 100644
--- a/infer/src/cost/costModels.ml
+++ b/infer/src/cost/costModels.ml
@@ -137,6 +137,7 @@ module JavaString = struct
 end
 
 module BoundsOfCollection = BoundsOf (CostUtils.Collection)
+module BoundsOfNSCollection = BoundsOf (CostUtils.NSCollection)
 module BoundsOfArray = BoundsOf (CostUtils.Array)
 module BoundsOfCString = BoundsOf (CostUtils.CString)
 
@@ -214,17 +215,26 @@ module Call = struct
           &:: "componentsSeparatedByString:" <>$ capt_exp $+ capt_exp
           $--> NSString.op_on_two_str BasicCost.mult
                  ~of_function:"NSString.componentsSeparatedByString:"
-        ; -"NSArray" &:: "initWithArray:" <>$ any_arg $+ capt_exp
-          $--> NSCollection.get_length ~of_function:"NSArray.initWithArray:"
-        ; -"NSArray" &:: "isEqualToArray:" <>$ capt_exp $+ capt_exp
+        ; +PatternMatch.ObjectiveC.implements "NSArray"
+          &:: "initWithArray:" <>$ any_arg $+ capt_exp
+          $--> BoundsOfNSCollection.linear_length ~of_function:"NSArray.initWithArray:"
+        ; +PatternMatch.ObjectiveC.implements "NSArray"
+          &:: "isEqualToArray:" <>$ capt_exp $+ capt_exp
           $--> NSCollection.op_on_two_coll BasicCost.min_default_left
                  ~of_function:"NSArray.isEqualToArray:"
-        ; -"NSArray" &:: "containsObject:" <>$ capt_exp $+ any_arg
-          $--> NSCollection.get_length ~of_function:"NSArray.containsObject:"
-        ; -"NSMutableArray" &:: "removeAllObjects" <>$ capt_exp
-          $--> NSCollection.get_length ~of_function:"NSArray.removeAllObjects"
-        ; -"NSMutableArray" &:: "addObjectsFromArray:" <>$ any_arg $+ capt_exp
-          $--> NSCollection.get_length ~of_function:"NSArray.addObjectsFromArray:"
+        ; +PatternMatch.ObjectiveC.implements "NSArray"
+          &:: "containsObject:" <>$ capt_exp $+ any_arg
+          $--> BoundsOfNSCollection.linear_length ~of_function:"NSArray.containsObject:"
+        ; +PatternMatch.ObjectiveC.implements "NSArray"
+          &:: "sortedArrayUsingDescriptors:" <>$ capt_exp $+ any_arg
+          $--> BoundsOfNSCollection.n_log_n_length
+                 ~of_function:"NSArray.sortedArrayUsingDescriptors:"
+        ; +PatternMatch.ObjectiveC.implements "NSMutableArray"
+          &:: "removeAllObjects" <>$ capt_exp
+          $--> BoundsOfNSCollection.linear_length ~of_function:"NSArray.removeAllObjects"
+        ; +PatternMatch.ObjectiveC.implements "NSMutableArray"
+          &:: "addObjectsFromArray:" <>$ any_arg $+ capt_exp
+          $--> BoundsOfNSCollection.linear_length ~of_function:"NSArray.addObjectsFromArray:"
         ; +PatternMatch.Java.implements_collections
           &:: "sort" $ capt_exp
           $+...$--> BoundsOfCollection.n_log_n_length ~of_function:"Collections.sort"
diff --git a/infer/src/cost/costUtils.ml b/infer/src/cost/costUtils.ml
index 3603349d8..9e1e91882 100644
--- a/infer/src/cost/costUtils.ml
+++ b/infer/src/cost/costUtils.ml
@@ -55,6 +55,11 @@ module Collection : S = struct
     BufferOverrunModels.Collection.eval_collection_length coll_exp inferbo_mem
 end
 
+module NSCollection : S = struct
+  let length coll_exp inferbo_mem =
+    BufferOverrunModels.NSCollection.eval_collection_length coll_exp inferbo_mem
+end
+
 module CString : S = struct
   let length exp inferbo_mem = BufferOverrunSemantics.eval_string_len exp inferbo_mem
 end
diff --git a/infer/tests/codetoanalyze/objc/performance/NSArray.m b/infer/tests/codetoanalyze/objc/performance/NSArray.m
index 64cb16a42..496c95372 100644
--- a/infer/tests/codetoanalyze/objc/performance/NSArray.m
+++ b/infer/tests/codetoanalyze/objc/performance/NSArray.m
@@ -137,7 +137,7 @@ NSArray* nsarray_sort_using_descriptors_constant() {
   return [array sortedArrayUsingDescriptors:@[ sd ]];
 }
 
-NSArray* nsarray_sort_using_descriptors_nlogn_FN(NSArray* array) {
+NSArray* nsarray_sort_using_descriptors_nlogn(NSArray* array) {
   NSSortDescriptor* sd = [[NSSortDescriptor alloc] initWithKey:nil
                                                      ascending:YES];
   return [array sortedArrayUsingDescriptors:@[ sd ]];
diff --git a/infer/tests/codetoanalyze/objc/performance/cost-issues.exp b/infer/tests/codetoanalyze/objc/performance/cost-issues.exp
index e7ae9a9f3..973c5063a 100644
--- a/infer/tests/codetoanalyze/objc/performance/cost-issues.exp
+++ b/infer/tests/codetoanalyze/objc/performance/cost-issues.exp
@@ -22,8 +22,8 @@ codetoanalyze/objc/performance/NSArray.m, nsarray_last_object_constant, 4,  OnUI
 codetoanalyze/objc/performance/NSArray.m, nsarray_next_object_constant, 25,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSArray.m, nsarray_next_object_linear, 5 + array->elements.length.ub + 4 ⋅ (array->elements.length.ub + 1),  OnUIThread:false, [{array->elements.length.ub + 1},Loop,{array->elements.length.ub},Loop]
 codetoanalyze/objc/performance/NSArray.m, nsarray_object_at_indexed_constant, 34,  OnUIThread:false, []
-codetoanalyze/objc/performance/NSArray.m, nsarray_sort_using_descriptors_constant, 34,  OnUIThread:false, []
-codetoanalyze/objc/performance/NSArray.m, nsarray_sort_using_descriptors_nlogn_FN, 10,  OnUIThread:false, []
+codetoanalyze/objc/performance/NSArray.m, nsarray_sort_using_descriptors_constant, 39,  OnUIThread:false, []
+codetoanalyze/objc/performance/NSArray.m, nsarray_sort_using_descriptors_nlogn, 9 + array->elements.length.ub × log(array->elements.length.ub),  OnUIThread:false, [{array->elements.length.ub},Modeled call to NSArray.sortedArrayUsingDescriptors:,{array->elements.length.ub},Modeled call to NSArray.sortedArrayUsingDescriptors:]
 codetoanalyze/objc/performance/NSArray.m, objc_blocknsarray_binary_search_log_FN_1, 5,  OnUIThread:false, []
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_all_keys_linear1, 3 + 3 ⋅ dict->elements.length.ub + 4 ⋅ (dict->elements.length.ub + 1),  OnUIThread:false, [{dict->elements.length.ub + 1},Loop,{dict->elements.length.ub},Loop]
 codetoanalyze/objc/performance/NSDictionary.m, nsdictionary_all_keys_linear2, 6 + 3 ⋅ dict->elements.length.ub + 3 ⋅ (dict->elements.length.ub + 1),  OnUIThread:false, [{dict->elements.length.ub + 1},Loop,{dict->elements.length.ub},Loop]