diff --git a/src/callback.c b/src/callback.c
index a04059d0..281b38f4 100644
--- a/src/callback.c
+++ b/src/callback.c
@@ -972,16 +972,18 @@ int callback(int event, int mx, int my, KeySym key,
    if(key=='k' && state==ControlMask)                           /* unhilight net */
    {
     xRect boundbox;
+    int big =  xctx->wires> 2000 || xctx->instances > 2000 ;
     if(semaphore >= 2) break;
-    calc_drawing_bbox(&boundbox, 2);
-
+    if(!big) calc_drawing_bbox(&boundbox, 2);
     unhilight_net();
     /* undraw_hilight_net(1); */
-    bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
-    bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
-    bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+    if(!big) {
+      bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
+      bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
+      bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+    }
     draw();
-    bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
+    if(!big) bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
     break;
    }
    if(key=='K' && state==(ControlMask|ShiftMask))       /* hilight net drilling thru elements  */
@@ -1006,16 +1008,19 @@ int callback(int event, int mx, int my, KeySym key,
    if(key=='K' && state == ShiftMask)                           /* delete hilighted nets */
    {
     xRect boundbox;
+    int big =  xctx->wires> 2000 || xctx->instances > 2000 ;
     if(semaphore >= 2) break;
     enable_drill=0;
-    calc_drawing_bbox(&boundbox, 2);
+    if(!big) calc_drawing_bbox(&boundbox, 2);
     delete_hilight_net();
     /* undraw_hilight_net(1); */
-    bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
-    bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
-    bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+    if(!big) {
+      bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
+      bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
+      bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+    }
     draw();
-    bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
+    if(!big) bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
     break;
    }
    if(key=='g' && state==Mod1Mask) { /* highlight net and send to gaw viewer */
@@ -1698,14 +1703,17 @@ int callback(int event, int mx, int my, KeySym key,
          xRect boundbox;
          if(auto_hilight && hilight_nets && sel == 0 ) { /* 20160413 20160503 */
            if(!prev_last_sel) {
-             calc_drawing_bbox(&boundbox, 2);
+             int big =  xctx->wires> 2000 || xctx->instances > 2000 ;
+             if(!big) calc_drawing_bbox(&boundbox, 2);
              delete_hilight_net();
              /* undraw_hilight_net(1); */
-             bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
-             bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
-             bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+             if(!big) {
+               bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
+               bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
+               bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+             }
              draw();
-             bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
+             if(!big) bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
            }
          }
        }
diff --git a/src/hilight.c b/src/hilight.c
index f816e52f..677c83d3 100644
--- a/src/hilight.c
+++ b/src/hilight.c
@@ -881,13 +881,16 @@ void unhilight_net(void)
 void redraw_hilights(void)
 {
   xRect boundbox;
+  int big =  xctx->wires> 2000 || xctx->instances > 2000 ;
   if(!has_x) return;
-  calc_drawing_bbox(&boundbox, 2);
-  bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
-  bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
-  bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+  if(!big) {
+    calc_drawing_bbox(&boundbox, 2);
+    bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
+    bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
+    bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+  }
   draw();
-  bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
+  if(!big) bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
 }
 
 void draw_hilight_net(int on_window)
diff --git a/src/scheduler.c b/src/scheduler.c
index e19bb065..b91a578b 100644
--- a/src/scheduler.c
+++ b/src/scheduler.c
@@ -1423,15 +1423,18 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
  else if(!strcmp(argv[1],"unhilight"))
  {
    xRect boundbox;
+   int big =  xctx->wires> 2000 || xctx->instances > 2000 ;
    enable_drill=0;
-   calc_drawing_bbox(&boundbox, 2);
+   if(!big) calc_drawing_bbox(&boundbox, 2);
    delete_hilight_net();
    /* undraw_hilight_net(1); */
-   bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
-   bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
-   bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+   if(!big) {
+     bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
+     bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
+     bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+   }
    draw();
-   bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
+   if(!big) bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
 
    /*
    enable_drill = 0;
diff --git a/src/token.c b/src/token.c
index b963c6fc..3e5d1fd9 100644
--- a/src/token.c
+++ b/src/token.c
@@ -180,19 +180,22 @@ void check_unique_names(int rename)
   char *comma_pos;
   char *expanded_instname = NULL;
   struct inst_hashentry *entry;
+  int big =  xctx->wires> 2000 || xctx->instances > 2000;
   /* int save_draw; */
 
   if(hilight_nets) {
     xRect boundbox;
-    calc_drawing_bbox(&boundbox, 2);
+    if(!big) calc_drawing_bbox(&boundbox, 2);
     enable_drill=0;
     delete_hilight_net();
     /* undraw_hilight_net(1); */
-    bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
-    bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
-    bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+    if(!big) {
+      bbox(BEGIN, 0.0 , 0.0 , 0.0 , 0.0);
+      bbox(ADD, boundbox.x1, boundbox.y1, boundbox.x2, boundbox.y2);
+      bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
+    }
     draw();
-    bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
+    if(!big) bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
   }
   inst_free_hash(table);
   first = 1;