diff --git a/benchmarks/block_size.py b/benchmarks/block_size.py
new file mode 100644
index 0000000..c30da4c
--- /dev/null
+++ b/benchmarks/block_size.py
@@ -0,0 +1,78 @@
+import math
+import pycuda.autoinit
+import pycuda.driver as drv
+import numpy as np
+from pycuda import gpuarray
+from pycuda.compiler import SourceModule
+
+from optparse import OptionParser
+
+ker = SourceModule("""
+__global__ void bench_int(const int limit, int *NUMBERS) {
+    unsigned int id = threadIdx.x + blockDim.x * blockIdx.x;
+    int num = NUMBERS[id];
+    for (int i = 0; i < limit; i++) {
+        num += i;
+    }
+    NUMBERS[id] = num;
+}
+""")
+
+
+def bench_block_size(grid_size: int, block_size: int, calc_count: int):
+    fetch_add = ker.get_function("bench_int")
+
+    vector_gpu = gpuarray.to_gpu(np.ones(block_size * grid_size).astype(np.intc))
+
+    startEvent = drv.Event()
+    endEvent = drv.Event()
+    startEvent.record()
+
+    fetch_add(np.int_(calc_count), vector_gpu, block=(block_size, 1, 1), grid=(grid_size, 1, 1))
+
+    endEvent.record()
+    endEvent.synchronize()
+
+    kernel_execution_time = startEvent.time_till(endEvent)
+    return (block_size * grid_size)/kernel_execution_time
+
+
+if __name__ == "__main__":
+    parser = OptionParser()
+    parser.add_option("--bench-output", dest="bench_output",
+                      help="The output file for timings", default="timings.csv", type="string")
+    parser.add_option("--calculation-steps", dest="calculation_steps",
+                      help=" How many calculations steps should be done per GPU thread", default="1000000", type="int")
+
+    parser.add_option("--grid_size", dest="grid_size",
+                      help="number of blocks", default="1024", type="int")
+    parser.add_option("--block_size_start", dest="block_size_start",
+                      help="initial number of threads per block", default="4",
+                      type="int")
+    parser.add_option("--block_size_step", dest="block_size_step",
+                      help="The amount the block size increases by every step", default="4",
+                      type="int")
+    parser.add_option("--block_size_stop", dest="block_size_stop",
+                      help="maximum number of threads per block, max = 1024", default="1024",
+                      type="int")
+    parser.add_option("--repetitions", dest="repetitions",
+                      help=" The average of n runs that is used instead of using one value only.", default="1",
+                      type="int")
+    (options, args) = parser.parse_args()
+    print(
+        "Benchmarking block size. Grid Size: {}, Start: {}, Step: {} ,Stop: {}, Calculations: {}, Repetitions: {}".format(
+            options.grid_size, options.block_size_start, options.block_size_step, options.block_size_stop, options.calculation_steps, options.repetitions))
+
+    with open(options.bench_output, 'w') as file:
+        file.write("block size,calls per second\n")
+
+    current_block_size = options.block_size_start
+
+    while current_block_size <= options.block_size_stop:
+        total_duration = 0
+        for i in range(0, options.repetitions):
+            duration = bench_block_size(options.grid_size, current_block_size, options.calculation_steps)
+            total_duration += duration
+        with open(options.bench_output, 'a') as file:
+            file.write(str(current_block_size) + "," + str(total_duration/options.repetitions) + "\n")
+        current_block_size += options.block_size_step
diff --git a/main.py b/main.py
index 86a59aa..6b3000a 100644
--- a/main.py
+++ b/main.py
@@ -109,13 +109,16 @@ def calc_primes(start: int = 1, grid_size: int = 1000, block_size: int = 1024):
 if __name__ == "__main__":
     parser = OptionParser()
     parser.add_option("-e", "--end", dest="end",
-                      help="numbers to check without even numbers", default="5000000000", type="int")
+                      help="numbers to check without even numbers", default="50000000", type="int")
     parser.add_option("--numbers-per-step", dest="numbers_per_step",
                       help="amount of uneven numbers checked in each step (even number are skipped)", default="8000000",
                       type="int")
     parser.add_option("--block_size", dest="block_size",
                       help="number of threads per block, max = 1024", default="1024",
                       type="int")
+    parser.add_option("--grid_size", dest="grid_size",
+                      help="number of blocks in the grid",
+                      type="int")
     parser.add_option("--output", dest="output",
                       help="name of the file, where the primes should be stored", default="primes.txt", type="string")
     parser.add_option("--timings-output", dest="timings_output",