diff --git a/Makefile b/Makefile
index 76f3709..7986ebb 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 #CONFIGURE BUILD SYSTEM
 TARGET	   = MDBench-$(TAG)-$(OPT_SCHEME)
-BUILD_DIR  = ./$(TAG)
+BUILD_DIR  = ./$(TAG)-$(OPT_SCHEME)
 SRC_DIR    = ./$(OPT_SCHEME)
 ASM_DIR    = ./asm
 MAKE_DIR   = ./
diff --git a/lammps/force_lj.c b/lammps/force_lj.c
index 73c0269..5baa1e7 100644
--- a/lammps/force_lj.c
+++ b/lammps/force_lj.c
@@ -87,6 +87,11 @@ double computeForceLJ(Parameter *param, Atom *atom, Neighbor *neighbor, Stats *s
                 fix += delx * force;
                 fiy += dely * force;
                 fiz += delz * force;
+#ifdef USE_REFERENCE_VERSION
+                addStat(stats->atoms_within_cutoff, 1);
+            } else {
+                addStat(stats->atoms_outside_cutoff, 1);
+#endif
             }
         }
 
diff --git a/lammps/includes/stats.h b/lammps/includes/stats.h
index 231119b..7b99870 100644
--- a/lammps/includes/stats.h
+++ b/lammps/includes/stats.h
@@ -28,6 +28,8 @@
 typedef struct {
     long long int total_force_neighs;
     long long int total_force_iters;
+    long long int atoms_within_cutoff;
+    long long int atoms_outside_cutoff;
 } Stats;
 
 void initStats(Stats *s);
diff --git a/lammps/stats.c b/lammps/stats.c
index defaeac..1df7e5c 100644
--- a/lammps/stats.c
+++ b/lammps/stats.c
@@ -8,17 +8,22 @@
 void initStats(Stats *s) {
     s->total_force_neighs = 0;
     s->total_force_iters = 0;
+    s->atoms_within_cutoff = 0;
+    s->atoms_outside_cutoff = 0;
 }
 
 void displayStatistics(Atom *atom, Parameter *param, Stats *stats, double *timer) {
 #ifdef COMPUTE_STATS
+
     double force_useful_volume = 1e-9 * ( (double)(atom->Nlocal * (param->ntimes + 1)) * (sizeof(MD_FLOAT) * 6 + sizeof(int)) +
                                           (double)(stats->total_force_neighs) * (sizeof(MD_FLOAT) * 3 + sizeof(int)) );
     double avg_neigh = stats->total_force_neighs / (double)(atom->Nlocal * (param->ntimes + 1));
     double avg_simd = stats->total_force_iters / (double)(atom->Nlocal * (param->ntimes + 1));
-#ifdef EXPLICIT_TYPES
+
+    #ifdef EXPLICIT_TYPES
     force_useful_volume += 1e-9 * (double)((atom->Nlocal * (param->ntimes + 1)) + stats->total_force_neighs) * sizeof(int);
-#endif
+    #endif
+
     printf("Statistics:\n");
     printf("\tVector width: %d, Processor frequency: %.4f GHz\n", VECTOR_WIDTH, param->proc_freq);
     printf("\tAverage neighbors per atom: %.4f\n", avg_neigh);
@@ -27,5 +32,11 @@ void displayStatistics(Atom *atom, Parameter *param, Stats *stats, double *timer
     printf("\tTotal number of SIMD iterations: %lld\n", stats->total_force_iters);
     printf("\tUseful read data volume for force computation: %.2fGB\n", force_useful_volume);
     printf("\tCycles/SIMD iteration: %.4f\n", timer[FORCE] * param->proc_freq * 1e9 / stats->total_force_iters);
+
+    #ifdef USE_REFERENCE_VERSION
+    const double eff_pct = (double)stats->atoms_within_cutoff / (double)(stats->atoms_within_cutoff + stats->atoms_outside_cutoff) * 100.0;
+    printf("\tAtoms within/outside cutoff radius: %lld/%lld (%.2f%%)\n", stats->atoms_within_cutoff, stats->atoms_outside_cutoff, eff_pct);
+    #endif
+
 #endif
 }