diff --git a/stream_test.go b/stream_test.go
index 748ff2c..5d8dea7 100644
--- a/stream_test.go
+++ b/stream_test.go
@@ -136,3 +136,28 @@ func TestMerkleHashWriter(t *testing.T) {
 	}
 
 }
+
+var bench = NewHash(DefaultHashMaker, 8192)
+var buf = make([]byte, 8192)
+
+func benchmarkSize(b *testing.B, size int) {
+	b.SetBytes(int64(size))
+	sum := make([]byte, bench.Size())
+	for i := 0; i < b.N; i++ {
+		bench.Reset()
+		bench.Write(buf[:size])
+		bench.Sum(sum[:0])
+	}
+}
+
+func BenchmarkHash8Bytes(b *testing.B) {
+	benchmarkSize(b, 8)
+}
+
+func BenchmarkHash1K(b *testing.B) {
+	benchmarkSize(b, 1024)
+}
+
+func BenchmarkHash8K(b *testing.B) {
+	benchmarkSize(b, 8192)
+}