diff --git a/C-optimized/makefile b/C-optimized/makefile
index dc96b32a..ded7c6bb 100644
--- a/C-optimized/makefile
+++ b/C-optimized/makefile
@@ -46,6 +46,8 @@ multi:
 	OMP_NUM_THREADS=1 ./$(OUTPUT) && echo
 	OMP_NUM_THREADS=2 ./$(OUTPUT) && echo
 	OMP_NUM_THREADS=4 ./$(OUTPUT) && echo
+	OMP_NUM_THREADS=8 ./$(OUTPUT) && echo
+	OMP_NUM_THREADS=16 ./$(OUTPUT) && echo
 	./$(OUTPUT_ONE_THREAD) && echo
 
 time-linux:
@@ -53,6 +55,8 @@ time-linux:
 	OMP_NUM_THREADS=1 /bin/time -f "Time: %es" ./$(OUTPUT) && echo
 	OMP_NUM_THREADS=2 /bin/time -f "Time: %es" ./$(OUTPUT) && echo
 	OMP_NUM_THREADS=4 /bin/time -f "Time: %es" ./$(OUTPUT) && echo
+	OMP_NUM_THREADS=8 /bin/time -f "Time: %es" ./$(OUTPUT) && echo
+	OMP_NUM_THREADS=16 /bin/time -f "Time: %es" ./$(OUTPUT) && echo
 	/bin/time -f "Time: %es" ./$(OUTPUT_ONE_THREAD) && echo
 
 debian-install-dependencies:
diff --git a/C-optimized/out/samples b/C-optimized/out/samples
index 98384ccc..e77b2300 100755
Binary files a/C-optimized/out/samples and b/C-optimized/out/samples differ
diff --git a/C-optimized/samples.c b/C-optimized/samples.c
index 134c7dc2..d96bf519 100644
--- a/C-optimized/samples.c
+++ b/C-optimized/samples.c
@@ -6,7 +6,7 @@
 
 const float PI = 3.14159265358979323846;
 
-#define N 100000000
+#define N 10000000
 
 //Array helpers
 
@@ -50,6 +50,8 @@ void array_cumsum(float* array_to_sum, float* array_cumsummed, int length)
 float rand_float(float to, unsigned int* seed)
 {
     return ((float)rand_r(seed) / (float)RAND_MAX) * to;
+		// See: <https://stackoverflow.com/questions/43151361/how-to-create-thread-safe-random-number-generator-in-c-using-rand-r>
+		// rand() is not thread-safe, as it relies on (shared) hidden state.
 }
 
 float ur_normal(unsigned int* seed)