diff --git a/CloneSource.cpp b/CloneSource.cpp
index 287187f..5952269 100644
--- a/CloneSource.cpp
+++ b/CloneSource.cpp
@@ -35,7 +35,7 @@ const char* CloneSource::cloning_provenance_label[2] = { "Original texture", "Po
 
 
 CloneSource::CloneSource(Source *origin, uint64_t id) : Source(id), origin_(origin), cloningsurface_(nullptr),
-    to_delete_(nullptr), delay_(0.0), paused_(false), provenance_(CLONE_TEXTURE)
+    garbage_image_(nullptr), delay_(0.0), paused_(false), provenance_(CLONE_TEXTURE)
 {
     // initial name copies the origin name: diplucates are namanged in session
     name_ = origin->name();
@@ -152,18 +152,19 @@ void CloneSource::update(float dt)
         if (!paused_ && cloningsurface_ != nullptr) {
 
             // if temporary FBO was pending to be deleted, delete it now
-            if (to_delete_ != nullptr) {
-                delete to_delete_;
-                to_delete_ = nullptr;
+            if (garbage_image_ != nullptr) {
+                delete garbage_image_;
+                garbage_image_ = nullptr;
             }
 
             // What time is it?
             double now = g_timer_elapsed (timer_, NULL);
 
             // is the total buffer of images longer than delay ?
-            if ( !images_.empty() && now - elapsed_.front() > delay_ ) {
+            if ( !images_.empty() && now - elapsed_.front() > delay_ )
+            {
                 // remember FBO to be reused if needed (see below) or deleted later
-                to_delete_ = images_.front();
+                garbage_image_ = images_.front();
                 // remove element from queue (front)
                 images_.pop();
                 elapsed_.pop();
@@ -171,16 +172,24 @@ void CloneSource::update(float dt)
             }
 
             // add image to queue to accumulate buffer images until delay reached
-            if ( images_.empty() || now - elapsed_.front() < delay_ + (dt * 0.001) ) {
-                // create a FBO if none can be reused (from above)
-                if (to_delete_ == nullptr)
-                    to_delete_ = new FrameBuffer( origin_->frame()->resolution(), origin_->frame()->use_alpha() );
-                // add element to queue (back)
-                images_.push( to_delete_ );
-                elapsed_.push( now );
-                timestamps_.push( origin_->playtime() );
-                // to_delete_ FBO is now used, should not be deleted
-                to_delete_ = nullptr;
+            if ( images_.empty() || now - elapsed_.front() < delay_ + (dt * 0.001) )
+            {
+                // create a FBO if none can be reused (from above) and test for RAM in GPU
+                if (garbage_image_ == nullptr && ( images_.empty() || FrameBuffer::shouldHaveEnoughMemory(origin_->frame()->resolution(), origin_->frame()->use_alpha()) ) )
+                    garbage_image_ = new FrameBuffer( origin_->frame()->resolution(), origin_->frame()->use_alpha() );
+                // no image available
+                if (garbage_image_ != nullptr) {
+                    // add element to queue (back)
+                    images_.push( garbage_image_ );
+                    elapsed_.push( now );
+                    timestamps_.push( origin_->playtime() );
+                    // garbage_image_ FBO is now used, it should not be deleted
+                    garbage_image_ = nullptr;
+                }
+                else {
+                    delay_ = now - elapsed_.front() - (dt * 0.001);
+                    Log::Warning("Cannot satisfy delay for Clone %s: not enough RAM in graphics card.", name_.c_str());
+                }
             }
 
             // CLONE_RENDER : blit rendered framebuffer in the newest image (back)
@@ -232,16 +241,17 @@ bool CloneSource::playable () const
 void CloneSource::replay()
 {
     // clear to_delete_ FBO if pending
-    if (to_delete_ != nullptr) {
-        delete to_delete_;
-        to_delete_ = nullptr;
+    if (garbage_image_ != nullptr) {
+        g_printerr(" REPLAY delete garbage %d \n", garbage_image_->opengl_id());
+        delete garbage_image_;
+        garbage_image_ = nullptr;
     }
 
     // remove all images except the one in the back (newest)
     while (images_.size() > 1) {
         // do not delete immediately the (oldest) front image (the FBO is currently displayed)
-        if (to_delete_ == nullptr)
-            to_delete_ = images_.front();
+        if (garbage_image_ == nullptr)
+            garbage_image_ = images_.front();
         // delete other FBO (unused)
         else if (images_.front() != nullptr)
             delete images_.front();
diff --git a/CloneSource.h b/CloneSource.h
index 0e096f3..137486c 100644
--- a/CloneSource.h
+++ b/CloneSource.h
@@ -55,7 +55,7 @@ protected:
     // cloning & queue of past frames
     std::queue<FrameBuffer *> images_;
     Surface *cloningsurface_;
-    FrameBuffer *to_delete_;
+    FrameBuffer *garbage_image_;
 
     // time management
     GTimer *timer_;
diff --git a/FrameBuffer.cpp b/FrameBuffer.cpp
index 4db8ef9..b086aec 100644
--- a/FrameBuffer.cpp
+++ b/FrameBuffer.cpp
@@ -32,7 +32,7 @@
 #include <stb_image_write.h>
 
 #ifndef NDEBUG
-//#define FRAMEBUFFER_DEBUG
+#define FRAMEBUFFER_DEBUG
 #endif
 
 #define GL_GPU_MEM_INFO_TOTAL_AVAILABLE_MEM_NVX 0x9048
@@ -140,7 +140,7 @@ void FrameBuffer::init()
         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureid_, 0);
 
 #ifdef FRAMEBUFFER_DEBUG
-        g_printerr("New FBO %d Multi Sampling ", framebufferid_);
+        g_printerr("New FBO %d Multi Sampling\n", framebufferid_);
 #endif
     }
     else {
@@ -149,7 +149,7 @@ void FrameBuffer::init()
         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureid_, 0);
 
 #ifdef FRAMEBUFFER_DEBUG
-        g_printerr("New FBO %d Single Sampling ", framebufferid_);
+        g_printerr("New FBO %d Single Sampling\n", framebufferid_);
 #endif
 
     }
@@ -171,8 +171,8 @@ FrameBuffer::~FrameBuffer()
         glDeleteTextures(1, &intermediate_textureid_);
 
 #ifdef FRAMEBUFFER_DEBUG
-    GLint framebufferMemoryInKB = ( width() * height() * 5 ) / 1024;
-    g_printerr("Framebuffer deleted %d x %d, %d kB freed\n", width(), height(), framebufferMemoryInKB);
+    GLint framebufferMemoryInKB = ( width() * height() * (use_alpha_?4:3) ) / 1024;
+    g_printerr("Framebuffer deleted %d x %d, ~%d kB freed\n", width(), height(), framebufferMemoryInKB);
 #endif
 }
 
@@ -313,102 +313,129 @@ void FrameBuffer::checkFramebufferStatus()
 {
     GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
     switch (status){
-        case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
-            Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT​ is returned if any of the framebuffer attachment points are framebuffer incomplete.");
-            break;
-        case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
-            Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT​ is returned if the framebuffer does not have at least one image attached to it.");
-            break;
-        case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER:
-            Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER​ is returned if the value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE​ is GL_NONE​ for any color "
-            "attachment point(s) named by GL_DRAWBUFFERi​.");
-            break;
-        case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER:
-            Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER​ is returned if GL_READ_BUFFER​ is not GL_NONE​ and the value of "
-            "GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE​ is GL_NONE​ for the color attachment point named by GL_READ_BUFFER.");
-            break;
-        case GL_FRAMEBUFFER_UNSUPPORTED:
-            Log::Warning("GL_FRAMEBUFFER_UNSUPPORTED​ is returned if the combination of internal formats of the attached images violates an "
-            "implementation-dependent set of restrictions.");
-            break;
-        case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE:
-            Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE​ is returned if the value of GL_RENDERBUFFER_SAMPLES​ is not the same for all attached renderbuffers; "
-            "if the value of GL_TEXTURE_SAMPLES​ is the not same for all attached textures; or, if the attached images are a mix of renderbuffers and textures, the value of "
-            "GL_RENDERBUFFER_SAMPLES​ does not match the value of GL_TEXTURE_SAMPLES.\nGL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE​ is also returned if the value of "
-            "GL_TEXTURE_FIXED_SAMPLE_LOCATIONS​ is not the same for all attached textures; or, if the attached images are a mix of renderbuffers and textures, "
-            "the value of GL_TEXTURE_FIXED_SAMPLE_LOCATIONS​ is not GL_TRUE​ for all attached textures.");
-            break;
-        case GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS:
-            Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS​ is returned if any framebuffer attachment is layered, and any populated attachment is not layered,"
-            " or if all populated color attachments are not from textures of the same target.");
-            break;
-        case GL_FRAMEBUFFER_UNDEFINED:
-            Log::Warning(" GL_FRAMEBUFFER_UNDEFINED​ is returned if target​ is the default framebuffer, but the default framebuffer does not exist.");
-            break;
-        case GL_FRAMEBUFFER_COMPLETE:
-
+    case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
+        Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT​ is returned if any of the framebuffer attachment points are framebuffer incomplete.");
+        break;
+    case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
+        Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT​ is returned if the framebuffer does not have at least one image attached to it.");
+        break;
+    case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER:
+        Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER​ is returned if the value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE​ is GL_NONE​ for any color "
+                     "attachment point(s) named by GL_DRAWBUFFERi​.");
+        break;
+    case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER:
+        Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER​ is returned if GL_READ_BUFFER​ is not GL_NONE​ and the value of "
+                     "GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE​ is GL_NONE​ for the color attachment point named by GL_READ_BUFFER.");
+        break;
+    case GL_FRAMEBUFFER_UNSUPPORTED:
+        Log::Warning("GL_FRAMEBUFFER_UNSUPPORTED​ is returned if the combination of internal formats of the attached images violates an "
+                     "implementation-dependent set of restrictions.");
+        break;
+    case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE:
+        Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE​ is returned if the value of GL_RENDERBUFFER_SAMPLES​ is not the same for all attached renderbuffers; "
+                     "if the value of GL_TEXTURE_SAMPLES​ is the not same for all attached textures; or, if the attached images are a mix of renderbuffers and textures, the value of "
+                     "GL_RENDERBUFFER_SAMPLES​ does not match the value of GL_TEXTURE_SAMPLES.\nGL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE​ is also returned if the value of "
+                     "GL_TEXTURE_FIXED_SAMPLE_LOCATIONS​ is not the same for all attached textures; or, if the attached images are a mix of renderbuffers and textures, "
+                     "the value of GL_TEXTURE_FIXED_SAMPLE_LOCATIONS​ is not GL_TRUE​ for all attached textures.");
+        break;
+    case GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS:
+        Log::Warning("GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS​ is returned if any framebuffer attachment is layered, and any populated attachment is not layered,"
+                     " or if all populated color attachments are not from textures of the same target.");
+        break;
+    case GL_FRAMEBUFFER_UNDEFINED:
+        Log::Warning(" GL_FRAMEBUFFER_UNDEFINED​ is returned if target​ is the default framebuffer, but the default framebuffer does not exist.");
+        break;
+    case GL_FRAMEBUFFER_COMPLETE:
         {
-            static int meminfomode = -1;
-            // first time check which way to get memory info
-            if (meminfomode<0) {
-                meminfomode = 0;
-                GLint numExtensions = 0;
-                glGetIntegerv( GL_NUM_EXTENSIONS, &numExtensions );
-                for (int i = 0; i < numExtensions; ++i){
 
-                    const GLubyte *ccc = glGetStringi(GL_EXTENSIONS, i);
-                    if ( strcmp( (const char*)ccc, "GL_NVX_gpu_memory_info") == 0 ){
-                        meminfomode = 1;
-                        break;
-                    }
-                    else if ( strcmp( (const char*)ccc, "GL_ATI_meminfo") == 0 ){
-                        meminfomode = 2;
-                        break;
-                    }
-                }
+        // approximation of RAM needed for this FBO
+        GLint framebufferMemoryInKB = ( width() * height() * (use_alpha_?4:3) * (use_multi_sampling_?2:1) ) / 1024;
 
-            }
+        // test available memory if created buffer is big (more than 8MB)
+        if ( framebufferMemoryInKB > 8000 ) {
 
-            GLint framebufferMemoryInKB = ( width() * height() * 5 ) / 1024;
+            // Obtain RAM usage in GPU (if possible)
+            glm::ivec2 RAM = getGPUMemoryInformation();
 
-            // NVIDIA
-            if (meminfomode == 1) {
-                static GLint nTotalMemoryInKB = -1;
-                if (nTotalMemoryInKB<0)
-                    glGetIntegerv( GL_GPU_MEM_INFO_TOTAL_AVAILABLE_MEM_NVX,  &nTotalMemoryInKB );
-
-                GLint nCurAvailMemoryInKB = 0;
-                glGetIntegerv( GL_GPU_MEM_INFO_CURRENT_AVAILABLE_MEM_NVX, &nCurAvailMemoryInKB );
-
-                if ( nCurAvailMemoryInKB < framebufferMemoryInKB )
-                    Log::Warning("Cannot allocate frame buffer: only %d kB GPU RAM remaining on the %d kB available (%d %%).",
-                                 nCurAvailMemoryInKB, nTotalMemoryInKB, int(float(nCurAvailMemoryInKB) / float(nTotalMemoryInKB) * 100.f  ) );
-#ifdef FRAMEBUFFER_DEBUG
-                else
-                    g_printerr("Framebuffer created %d x %d, %d kB allocated (%d kB remaining on %d kB)\n", width(), height(), framebufferMemoryInKB, nCurAvailMemoryInKB, nTotalMemoryInKB);
-#endif
-            }
-            // ATI
-            else if (meminfomode == 2) {
-
-                GLint nCurAvailMemoryInKB = 0;
-                glGetIntegerv( GL_TEXTURE_FREE_MEMORY_ATI, &nCurAvailMemoryInKB );
-
-                if ( nCurAvailMemoryInKB < framebufferMemoryInKB )
-                    Log::Warning("Cannot allocate frame buffer: only %d kB GPU RAM remaining.", nCurAvailMemoryInKB );
-#ifdef FRAMEBUFFER_DEBUG
-                else
-                    g_printerr("Framebuffer created %d x %d, %d kB allocated (%d kB remaining)\n", width(), height(), framebufferMemoryInKB, nCurAvailMemoryInKB);
-#endif
+            // bad case: not enough RAM, we should warn the user
+            if ( RAM.x < framebufferMemoryInKB * 3 ) {
+                Log::Warning("Critical allocation of frame buffer: only %d kB RAM remaining in graphics card.", RAM.x );
+                if (RAM.y < INT_MAX)
+                    Log::Warning("Only %.1f %% of %d kB available.", 100.f*float(RAM.x)/float(RAM.y), RAM.y);
             }
 #ifdef FRAMEBUFFER_DEBUG
-             else
-                g_printerr("Framebuffer created %d x %d, %d kB allocated\n", width(), height(), framebufferMemoryInKB);
+            else {
+                // normal case: enough RAM (or unknown) for this FBO
+                g_printerr("Framebuffer allocated %d x %d, ~%d kB", width(), height(), framebufferMemoryInKB);
+                if (RAM.x < INT_MAX)
+                    g_printerr(" (%d kB remaining)", RAM.x);
+                g_printerr("\n");
+            }
 #endif
+        }
 
         }
         break;
     }
+
+}
+
+// RAM usage in GPU
+// returns { CurAvailMemoryInKB, TotalMemoryInKB }
+// MAX values means the info in not available
+glm::ivec2 FrameBuffer::getGPUMemoryInformation()
+{
+    glm::ivec2 ret(INT_MAX, INT_MAX);
+
+    // Detect method to get info
+    static int meminfomode = -1;
+    if (meminfomode<0) {
+        // initialized
+        meminfomode = 0;
+        GLint numExtensions = 0;
+        glGetIntegerv( GL_NUM_EXTENSIONS, &numExtensions );
+        for (int i = 0; i < numExtensions; ++i){
+            const GLubyte *ccc = glGetStringi(GL_EXTENSIONS, i);
+            // NVIDIA extension available
+            if ( strcmp( (const char*)ccc, "GL_NVX_gpu_memory_info") == 0 ){
+                meminfomode = 1;
+                break;
+            }
+            // ATI extension available
+            else if ( strcmp( (const char*)ccc, "GL_ATI_meminfo") == 0 ){
+                meminfomode = 2;
+                break;
+            }
+        }
+
+    }
+
+    // NVIDIA
+    if (meminfomode == 1) {
+        static GLint nTotalMemoryInKB = -1;
+        if (nTotalMemoryInKB<0)
+            glGetIntegerv( GL_GPU_MEM_INFO_TOTAL_AVAILABLE_MEM_NVX,  &nTotalMemoryInKB );
+        ret.y = nTotalMemoryInKB;
+
+        glGetIntegerv( GL_GPU_MEM_INFO_CURRENT_AVAILABLE_MEM_NVX, &ret.x );
+    }
+    // ATI
+    else if (meminfomode == 2) {
+        glGetIntegerv( GL_TEXTURE_FREE_MEMORY_ATI, &ret.x );
+    }
+
+    return ret;
+}
+
+
+bool FrameBuffer::shouldHaveEnoughMemory(glm::vec3 resolution, bool useAlpha, bool multiSampling)
+{
+    glm::ivec2 RAM = getGPUMemoryInformation();
+
+    // approximation of RAM needed for such FBO
+    GLint framebufferMemoryInKB = ( resolution.x * resolution.x * (useAlpha?4:3) * (multiSampling?2:1) ) / 1024;
+
+    return ( RAM.x > framebufferMemoryInKB * 3 );
 }
 
 
diff --git a/FrameBuffer.h b/FrameBuffer.h
index 0079916..4285a07 100644
--- a/FrameBuffer.h
+++ b/FrameBuffer.h
@@ -44,8 +44,9 @@ public:
     static float resolution_height[5];
     static glm::vec3 getResolutionFromParameters(int ar, int h);
     static glm::ivec2 getParametersFromResolution(glm::vec3 res);
-    // unbind any framebuffer object
-    static void release();
+    // memory management
+    static glm::ivec2 getGPUMemoryInformation();
+    static bool shouldHaveEnoughMemory(glm::vec3 resolution, bool useAlpha = false, bool multiSampling = false);
 
     FrameBuffer(glm::vec3 resolution, bool useAlpha = false, bool multiSampling = false);
     FrameBuffer(uint width, uint height, bool useAlpha = false, bool multiSampling = false);
@@ -56,6 +57,8 @@ public:
     void begin(bool clear = true);
     // pop attrib and unbind to end draw
     void end();
+    // unbind (any) framebuffer object
+    static void release();
     // blit copy to another, returns true on success
     bool blit(FrameBuffer *destination);
     // bind the FrameBuffer in READ and perform glReadPixels
@@ -101,7 +104,6 @@ private:
     uint textureid_, intermediate_textureid_;
     uint framebufferid_, intermediate_framebufferid_;
     bool use_alpha_, use_multi_sampling_;
-
 };