diff --git a/cocos/base/CCDirector.cpp b/cocos/base/CCDirector.cpp
index be72136274..6672681e22 100644
--- a/cocos/base/CCDirector.cpp
+++ b/cocos/base/CCDirector.cpp
@@ -117,7 +117,7 @@ bool Director::init(void)
     _accumDt = 0.0f;
     _frameRate = 0.0f;
     _FPSLabel = _drawnBatchesLabel = _drawnVerticesLabel = nullptr;
-    _totalFrames = _frames = 0;
+    _totalFrames = 0;
     _lastUpdate = new struct timeval;
 
     // paused ?
@@ -430,7 +430,13 @@ void Director::setNextDeltaTimeZero(bool nextDeltaTimeZero)
 {
     _nextDeltaTimeZero = nextDeltaTimeZero;
 }
-   
+
+//
+// FIXME TODO
+// Matrix code MUST NOT be part of the Director
+// MUST BE moved outide.
+// Why the Director must have this code ?
+//
 void Director::initMatrixStack()
 {
     while (!_modelViewMatrixStack.empty())
@@ -1069,22 +1075,26 @@ void Director::showStats()
 {
     static unsigned long prevCalls = 0;
     static unsigned long prevVerts = 0;
+    static float prevDeltaTime  = 0.016; // 60FPS
+    static const float FPS_FILTER = 0.05;
 
-    ++_frames;
     _accumDt += _deltaTime;
     
     if (_displayStats && _FPSLabel && _drawnBatchesLabel && _drawnVerticesLabel)
     {
         char buffer[30];
 
+        float dt = _deltaTime * FPS_FILTER + (1-FPS_FILTER) * prevDeltaTime;
+        prevDeltaTime = dt;
+
+        // Probably we don't need this anymore since
+        // the framerate is using a low-pass filter
+        // to make the FPS stable
         if (_accumDt > CC_DIRECTOR_STATS_INTERVAL)
         {
-            _frameRate = _frames / _accumDt;
-            _frames = 0;
-            _accumDt = 0;
-
-            sprintf(buffer, "%.1f / %.3f", _frameRate, _secondsPerFrame);
+            sprintf(buffer, "%.1f / %.3f", 1/dt, _secondsPerFrame);
             _FPSLabel->setString(buffer);
+            _accumDt = 0;
         }
 
         auto currentCalls = (unsigned long)_renderer->getDrawnBatches();
@@ -1101,8 +1111,8 @@ void Director::showStats()
             prevVerts = currentVerts;
         }
 
-        Mat4 identity = Mat4::IDENTITY;
 
+        Mat4 identity = Mat4::IDENTITY;
         _drawnVerticesLabel->visit(_renderer, identity, 0);
         _drawnBatchesLabel->visit(_renderer, identity, 0);
         _FPSLabel->visit(_renderer, identity, 0);
@@ -1111,10 +1121,16 @@ void Director::showStats()
 
 void Director::calculateMPF()
 {
+    static float prevSecondsPerFrame = 0;
+    static const float MPF_FILTER = 0.05;
+
     struct timeval now;
     gettimeofday(&now, nullptr);
     
     _secondsPerFrame = (now.tv_sec - _lastUpdate->tv_sec) + (now.tv_usec - _lastUpdate->tv_usec) / 1000000.0f;
+
+    _secondsPerFrame = _secondsPerFrame * MPF_FILTER + (1-MPF_FILTER) * prevSecondsPerFrame;
+    prevSecondsPerFrame = _secondsPerFrame;
 }
 
 // returns the FPS image data pointer and len
diff --git a/cocos/base/CCDirector.h b/cocos/base/CCDirector.h
index c9baba964a..5283d87db0 100644
--- a/cocos/base/CCDirector.h
+++ b/cocos/base/CCDirector.h
@@ -461,7 +461,6 @@ protected:
 
     /* How many frames were called since the director started */
     unsigned int _totalFrames;
-    unsigned int _frames;
     float _secondsPerFrame;
     
     /* The running scene */
diff --git a/tests/cpp-tests/Classes/FileUtilsTest/FileUtilsTest.cpp b/tests/cpp-tests/Classes/FileUtilsTest/FileUtilsTest.cpp
index f8154bc8f0..cc36d8aa0c 100644
--- a/tests/cpp-tests/Classes/FileUtilsTest/FileUtilsTest.cpp
+++ b/tests/cpp-tests/Classes/FileUtilsTest/FileUtilsTest.cpp
@@ -535,13 +535,13 @@ void TextWritePlist::onEnter()
     auto loadDict = __Dictionary::createWithContentsOfFile(fullPath.c_str());
     auto loadDictInDict = (__Dictionary*)loadDict->objectForKey("dictInDict, Hello World");
     auto boolValue = (__String*)loadDictInDict->objectForKey("bool");
-    CCLOG("%s",boolValue->getCString());
+    log("%s",boolValue->getCString());
     auto floatValue = (__String*)loadDictInDict->objectForKey("float");
-    CCLOG("%s",floatValue->getCString());
+    log("%s",floatValue->getCString());
     auto intValue = (__String*)loadDictInDict->objectForKey("integer");
-    CCLOG("%s",intValue->getCString());
+    log("%s",intValue->getCString());
     auto doubleValue = (__String*)loadDictInDict->objectForKey("double");
-    CCLOG("%s",doubleValue->getCString());
+    log("%s",doubleValue->getCString());
 
 }
 
diff --git a/tests/cpp-tests/Classes/UITest/CocoStudioGUITest/UIPageViewTest/UIPageViewTest.cpp b/tests/cpp-tests/Classes/UITest/CocoStudioGUITest/UIPageViewTest/UIPageViewTest.cpp
index f4b7d4478d..40afd20cff 100644
--- a/tests/cpp-tests/Classes/UITest/CocoStudioGUITest/UIPageViewTest/UIPageViewTest.cpp
+++ b/tests/cpp-tests/Classes/UITest/CocoStudioGUITest/UIPageViewTest/UIPageViewTest.cpp
@@ -185,10 +185,9 @@ bool UIPageViewButtonTest::init()
     return false;
 }
 
-void UIPageViewButtonTest::onButtonClicked(Ref* pSender, Widget::TouchEventType type)
+void UIPageViewButtonTest::onButtonClicked(Ref* sender, Widget::TouchEventType type)
 {
-    Button *btn = (Button*)pSender;
-    CCLOG("button %s clicked", btn->getName().c_str());
+    log("button %s clicked", static_cast<Button*>(sender)->getName().c_str());
 }
 
 
diff --git a/tests/cpp-tests/Classes/UnitTest/RefPtrTest.cpp b/tests/cpp-tests/Classes/UnitTest/RefPtrTest.cpp
index c42688e0df..209b81b88b 100644
--- a/tests/cpp-tests/Classes/UnitTest/RefPtrTest.cpp
+++ b/tests/cpp-tests/Classes/UnitTest/RefPtrTest.cpp
@@ -3,7 +3,8 @@
 void RefPtrTest::onEnter()
 {
     UnitTestDemo::onEnter();
-    
+
+#if DEBUG
     // TEST(constructors)
     {
         // Default constructor
@@ -313,6 +314,9 @@ void RefPtrTest::onEnter()
         CC_ASSERT(theString->getReferenceCount() == 2);
         CC_ASSERT(theString->compare("Hello world!") == 0);
     }
+#else
+    log("RefPtr tests are not executed in release mode");
+#endif
 }
 
 std::string RefPtrTest::subtitle() const
diff --git a/tests/cpp-tests/Classes/UnitTest/UnitTest.cpp b/tests/cpp-tests/Classes/UnitTest/UnitTest.cpp
index 0770c5ebf6..ac45999f67 100644
--- a/tests/cpp-tests/Classes/UnitTest/UnitTest.cpp
+++ b/tests/cpp-tests/Classes/UnitTest/UnitTest.cpp
@@ -697,7 +697,8 @@ void ValueTest::constFunc(const Value& value) const
 
 // UTFConversionTest
 
-static const int TEST_CODE_NUM = 11;
+// FIXME: made as define to prevent compile warnings in release mode. Better is to be a `const static int`
+#define TEST_CODE_NUM 11
 
 static const char16_t __utf16Code[] =
 {
@@ -818,8 +819,7 @@ static void doUTFConversion()
     CCASSERT(StringUtils::getCharacterCountInUTF8String(originalUTF8) == TEST_CODE_NUM, "StringUtils::getCharacterCountInUTF8String failed");
     
     //---------------------------
-    int lastIndex = StringUtils::getIndexOfLastNotChar16(vec3, 0x2009);
-    CCASSERT(lastIndex == (vec1.size()-1), "StringUtils::getIndexOfLastNotChar16 failed");
+    CCASSERT(StringUtils::getIndexOfLastNotChar16(vec3, 0x2009) == (vec1.size()-1), "StringUtils::getIndexOfLastNotChar16 failed");
     
     //---------------------------
     CCASSERT(originalUTF16.length() == TEST_CODE_NUM, "The length of the original utf16 string isn't equal to TEST_CODE_NUM");