diff --git a/4ed.cpp b/4ed.cpp
index fe70ef97..16dd347a 100644
--- a/4ed.cpp
+++ b/4ed.cpp
@@ -1653,6 +1653,7 @@ update_cli_handle_with_file(System_Functions *system, Models *models,
     return(result);
 }
 
+
 App_Step_Sig(app_step){
     Application_Step_Result app_result = *result;
     app_result.animating = 0;
@@ -1673,17 +1674,14 @@ App_Step_Sig(app_step){
     }
     
     // NOTE(allen): check files are up to date
-    {
-        File_Node *node, *used_nodes;
-        Editing_File *file;
-        u64 time_stamp;
-        
-        used_nodes = &models->working_set.used_sentinel;
-        for (dll_items(node, used_nodes)){
-            file = (Editing_File*)node;
+    if (!input->first_step){
+        Panel *panel = 0, *used_panels = &models->layout.used_sentinel;
+        for (dll_items(panel, used_panels)){
+            View *view = panel->view;
+            Editing_File *file = view->file_data.file;
             
             terminate_with_null(&file->name.source_path);
-            time_stamp = system->file_time_stamp(file->name.source_path.str);
+            u64 time_stamp = system->file_time_stamp(file->name.source_path.str);
             
             if (time_stamp > 0){
                 if (file->state.last_sync < time_stamp){
@@ -1691,6 +1689,36 @@ App_Step_Sig(app_step){
                 }
             }
         }
+        
+        File_Node *node = models->working_set.sync_check_iter;
+        File_Node *used_nodes = &models->working_set.used_sentinel;
+        
+        if (node == used_nodes){
+            node = node->next;
+        }
+        Assert(!((Editing_File*)node)->is_dummy);
+        
+        for (i32 i = 0; i < 4; ++i){
+            if (node == used_nodes){
+                break;
+            }
+            
+            Editing_File *file = (Editing_File*)node;
+            
+            terminate_with_null(&file->name.source_path);
+            u64 time_stamp = system->file_time_stamp(file->name.source_path.str);
+            
+            if (time_stamp > 0){
+                if (file->state.last_sync < time_stamp){
+                    file_mark_behind_os(file);
+                }
+            }
+        }
+        
+        models->working_set.sync_check_iter = node;
+    }
+    else{
+        models->working_set.sync_check_iter = &models->working_set.used_sentinel;
     }
     
     // NOTE(allen): reorganizing panels on screen
@@ -1700,8 +1728,8 @@ App_Step_Sig(app_step){
         i32 current_width = target->width;
         i32 current_height = target->height;
         
-        Panel *panel, *used_panels;
-        View *view;
+        Panel *panel = 0, *used_panels = &models->layout.used_sentinel;
+        View *view = 0;
         
         models->layout.full_width = current_width;
         models->layout.full_height = current_height;
@@ -1709,7 +1737,6 @@ App_Step_Sig(app_step){
         if (prev_width != current_width || prev_height != current_height){
             layout_refit(&models->layout, prev_width, prev_height);
             
-            used_panels = &models->layout.used_sentinel;
             for (dll_items(panel, used_panels)){
                 view = panel->view;
                 Assert(view);
@@ -2228,6 +2255,7 @@ App_Step_Sig(app_step){
             view->changed_context_in_step = 0;
             
             View_Step_Result result = step_file_view(system, view, active_view, summary);
+            
             if (result.animating){
                 app_result.animating = 1;
             }
@@ -2705,8 +2733,6 @@ App_Step_Sig(app_step){
     
     *result = app_result;
     
-    Assert(general_memory_check(&models->mem.general));
-    
     // end-of-app_step
 }
 
diff --git a/4ed_file.cpp b/4ed_file.cpp
index 6cd4e199..202d2564 100644
--- a/4ed_file.cpp
+++ b/4ed_file.cpp
@@ -215,6 +215,8 @@ struct Working_Set{
 	i32 clipboard_current, clipboard_rolling;
     
     u64 unique_file_counter;
+    
+    File_Node *sync_check_iter;
 };
 
 struct File_Entry{
@@ -457,6 +459,10 @@ working_set_alloc_always(Working_Set *working_set, General_Memory *general){
 
 inline void
 working_set_free_file(Working_Set  *working_set, Editing_File *file){
+    if (working_set->sync_check_iter == &file->node){
+        working_set->sync_check_iter = working_set->sync_check_iter->next;
+    }
+    
     file->is_dummy = 1;
     dll_remove(&file->node);
     dll_insert(&working_set->free_sentinel, &file->node);
diff --git a/internal_4coder_tests.cpp b/internal_4coder_tests.cpp
index 20782d8e..40386b30 100644
--- a/internal_4coder_tests.cpp
+++ b/internal_4coder_tests.cpp
@@ -18,14 +18,15 @@ Allen Webster
 
 #include <Windows.h>
 
-// NOTE(allen): This timing restriction is based on 4GHz and 60fps
-// 4G / 60 ~= 70M  Reserving most of that time for rendering and hopefully idling
-// I set the goal of 10M for all tests.
 #define TEST_TIME_B(m) DWORD64 time_start = __rdtsc(), time_max = m
 #define TEST_TIME_E() DWORD64 time_total = __rdtsc() - time_start; if (time_total > time_max) {assert(!"failed timing");}
 #define TEST_TIME_M(m) m = (float)(__rdtsc() - time_start) / time_max
 
 CUSTOM_COMMAND_SIG(load_lots_of_files){
+    
+    // NOTE(allen): This timing restriction is based on 4GHz and 60fps
+    // 4G / 60 ~= 70M  Reserving most of that time for rendering and hopefully idling
+    // I set the goal of 10M for all tests.
     TEST_TIME_B(10000000);
     
     File_List list = app->get_file_list(app, literal(LOTS_OF_FILES));
@@ -34,12 +35,13 @@ CUSTOM_COMMAND_SIG(load_lots_of_files){
     for (int i = 0; i < list.count; ++i, ++info){
         if (!info->folder){
             app->create_buffer(app, info->filename, info->filename_len,
-                               BufferCreate_Background | BufferCreate_AlwaysNew);
+                               BufferCreate_Background);
         }
     }
     
     app->free_file_list(app, list);
     
+    // TODO(allen): Pass this time test!
     TEST_TIME_E();
 }