diff --git a/app/config/config.cpp b/app/config/config.cpp
index cd0b7edc0..479f5b923 100644
--- a/app/config/config.cpp
+++ b/app/config/config.cpp
@@ -83,7 +83,7 @@ void Config::SetDefaults()
   config_map_["DropWithoutSequenceBehavior"] = TimelineWidget::kDWSAsk;
   config_map_["Loop"] = false;
 
-  config_map_["AutoCache"] = true;//false;//true;
+  config_map_["AutoCache"] = true;
   config_map_["AutoCacheInterval"] = 1000;
 
   config_map_["NodeCatColor0"] = QVariant::fromValue(Color(0.75f, 0.75f, 0.75f));
diff --git a/app/render/backend/renderbackend.cpp b/app/render/backend/renderbackend.cpp
index 26d575f25..f92385327 100644
--- a/app/render/backend/renderbackend.cpp
+++ b/app/render/backend/renderbackend.cpp
@@ -49,7 +49,10 @@ void RenderBackend::SetViewerNode(ViewerOutput *viewer_node)
     return;
   }
 
-  if (viewer_node_) {
+  ViewerOutput* old_viewer = viewer_node_;
+  viewer_node_ = viewer_node;
+
+  if (old_viewer) {
     // Delete all of our copied nodes
     pool_.clear();
     pool_.waitForDone();
@@ -61,19 +64,19 @@ void RenderBackend::SetViewerNode(ViewerOutput *viewer_node)
     render_queue_.clear();
 
     // Delete all the nodes
+    foreach (Node* c, copy_map_) {
+      c->DisconnectAll();
+    }
     qDeleteAll(copy_map_);
     copy_map_.clear();
     copied_viewer_node_ = nullptr;
 
-    disconnect(viewer_node_,
+    disconnect(old_viewer,
                &ViewerOutput::GraphChangedFrom,
                this,
                &RenderBackend::NodeGraphChanged);
   }
 
-  // Set viewer node
-  viewer_node_ = viewer_node;
-
   if (viewer_node_) {
     // Copy graph
     copied_viewer_node_ = static_cast<ViewerOutput*>(viewer_node_->copy());
@@ -107,7 +110,7 @@ void RenderBackend::ClearVideoQueue()
 
 QFuture<QList<QByteArray> > RenderBackend::Hash(const QList<rational> &times)
 {
-  return QtConcurrent::run([this](const QList<rational> &times){
+  return QtConcurrent::run(&pool_, [this](const QList<rational> &times){
     QList<QByteArray> hashes;
 
     foreach (const rational& t, times) {
@@ -155,6 +158,8 @@ RenderTicketPtr RenderBackend::RenderAudio(const TimeRange &r)
 
   render_queue_.append(ticket);
 
+  RunNextJob();
+
   return ticket;
 }
 
@@ -294,14 +299,16 @@ void RenderBackend::RunNextJob()
 
       switch (ticket->GetType()) {
       case RenderTicket::kTypeVideo:
-        QtConcurrent::run(worker,
+        QtConcurrent::run(&pool_,
+                          worker,
                           &RenderWorker::RenderFrame,
                           ticket,
                           copied_viewer_node_,
                           ticket->GetTime().in());
         break;
       case RenderTicket::kTypeAudio:
-        QtConcurrent::run(worker,
+        QtConcurrent::run(&pool_,
+                          worker,
                           &RenderWorker::RenderAudio,
                           ticket,
                           copied_viewer_node_,
@@ -319,9 +326,15 @@ void RenderBackend::RunNextJob()
 
 void RenderBackend::ProcessUpdateQueue()
 {
+  /*
   while (!graph_update_queue_.isEmpty()) {
     CopyNodeInputValue(graph_update_queue_.takeFirst());
   }
+  */
+
+  // FIXME: SLOW DEBUGGING CODE
+  CopyNodeInputValue(viewer_node_->texture_input());
+  CopyNodeInputValue(viewer_node_->samples_input());
 }
 
 void RenderBackend::WorkerFinished()
@@ -336,7 +349,11 @@ void RenderBackend::WorkerFinished()
     }
   }
 
-  RunNextJob();
+  if (viewer_node_) {
+    RunNextJob();
+  } else {
+    qDebug() << "Ignored job finish because no viewer";
+  }
 }
 
 void RenderBackend::CopyNodeInputValue(NodeInput *input)
diff --git a/app/render/backend/renderbackend.h b/app/render/backend/renderbackend.h
index 0025662b2..f428f09fe 100644
--- a/app/render/backend/renderbackend.h
+++ b/app/render/backend/renderbackend.h
@@ -57,12 +57,10 @@ public:
    */
   RenderTicketPtr RenderFrame(const rational& time);
 
-  QFuture<FramePtr> RenderFrames(const QList<rational>& frames);
-
   /**
    * @brief Asynchronously generate a chunk of audio
    */
-  QFuture<SampleBufferPtr> RenderAudio(const TimeRange& r);
+  RenderTicketPtr RenderAudio(const TimeRange& r);
 
   void SetVideoParams(const VideoRenderingParams& params);
 
diff --git a/app/render/backend/renderworker.cpp b/app/render/backend/renderworker.cpp
index f6864d266..a022a1f37 100644
--- a/app/render/backend/renderworker.cpp
+++ b/app/render/backend/renderworker.cpp
@@ -60,7 +60,7 @@ void RenderWorker::RenderFrame(RenderTicketPtr ticket, ViewerOutput* viewer, con
 
   ticket->Finish(QVariant::fromValue(frame));
 
-  FinishedJob();
+  emit FinishedJob();
 }
 
 void RenderWorker::RenderAudio(RenderTicketPtr ticket, ViewerOutput* viewer, const TimeRange &range)
@@ -71,7 +71,7 @@ void RenderWorker::RenderAudio(RenderTicketPtr ticket, ViewerOutput* viewer, con
 
   ticket->Finish(samples);
 
-  FinishedJob();
+  emit FinishedJob();
 }
 
 NodeValueTable RenderWorker::GenerateBlockTable(const TrackOutput *track, const TimeRange &range)
diff --git a/app/task/cache/cache.cpp b/app/task/cache/cache.cpp
index 348b21046..fd5b1985e 100644
--- a/app/task/cache/cache.cpp
+++ b/app/task/cache/cache.cpp
@@ -37,18 +37,20 @@ CacheTask::CacheTask(ViewerOutput* viewer, const VideoRenderingParams& vparams,
 bool CacheTask::Run()
 {
   // Get list of invalidated ranges
-  TimeRangeList range_to_cache = viewer()->video_frame_cache()->GetInvalidatedRanges();
+  TimeRangeList video_range = viewer()->video_frame_cache()->GetInvalidatedRanges();
+  TimeRangeList audio_range = viewer()->audio_playback_cache()->GetInvalidatedRanges();
 
   // If we're caching only in-out, limit the range to that
   if (in_out_only_) {
     Sequence* s = static_cast<Sequence*>(viewer()->parent());
 
     if (s->workarea()->enabled()) {
-      range_to_cache = range_to_cache.Intersects(s->workarea()->range());
+      video_range = video_range.Intersects(s->workarea()->range());
+      audio_range = audio_range.Intersects(s->workarea()->range());
     }
   }
 
-  Render(range_to_cache, QMatrix4x4(), false, true);
+  Render(video_range, audio_range, QMatrix4x4(), true);
 
   download_threads_.waitForDone();
 
@@ -67,4 +69,9 @@ void CacheTask::FrameDownloaded(const QByteArray &hash, const QLinkedList<ration
   }
 }
 
+void CacheTask::AudioDownloaded(const TimeRange &range, SampleBufferPtr samples)
+{
+  viewer()->audio_playback_cache()->WritePCM(range, samples);
+}
+
 OLIVE_NAMESPACE_EXIT
diff --git a/app/task/cache/cache.h b/app/task/cache/cache.h
index d49afa53e..66d4a4661 100644
--- a/app/task/cache/cache.h
+++ b/app/task/cache/cache.h
@@ -44,6 +44,8 @@ protected:
 
   virtual void FrameDownloaded(const QByteArray& hash, const QLinkedList<rational>& times) override;
 
+  virtual void AudioDownloaded(const TimeRange& range, SampleBufferPtr samples) override;
+
 private:
   bool in_out_only_;
 
diff --git a/app/task/export/export.cpp b/app/task/export/export.cpp
index 587af6ab1..3371b2c49 100644
--- a/app/task/export/export.cpp
+++ b/app/task/export/export.cpp
@@ -85,7 +85,17 @@ bool ExportTask::Run()
   }
 
   // Start render process
-  Render({range}, mat, params_.audio_enabled(), false);
+  TimeRangeList video_range, audio_range;
+
+  if (params_.video_enabled()) {
+    video_range.append(range);
+  }
+
+  if (params_.audio_enabled()) {
+    audio_range.append(range);
+  }
+
+  Render(video_range, audio_range, mat, false);
 
   bool success = true;
 
@@ -167,8 +177,6 @@ void ExportTask::AudioDownloaded(const TimeRange &range, SampleBufferPtr samples
     adjusted_range -= params_.custom_range().in();
   }
 
-  qDebug() << "Downloaded audio" << adjusted_range;
-
   audio_data_.WritePCM(adjusted_range, samples);
 }
 
diff --git a/app/task/render/render.cpp b/app/task/render/render.cpp
index ff799f104..a83554871 100644
--- a/app/task/render/render.cpp
+++ b/app/task/render/render.cpp
@@ -57,81 +57,25 @@ struct HashDownloadFuturePair {
   QFuture<void> download_future;
 };
 
-void RenderTask::Render(const TimeRangeList& range_to_cache,
+void RenderTask::Render(const TimeRangeList& video_range,
+                        const TimeRangeList &audio_range,
                         const QMatrix4x4& mat,
-                        bool audio_enabled,
                         bool use_disk_cache)
 {
   OpenGLBackend backend;
 
   backend.moveToThread(qApp->thread());
 
+  // FIXME: This makes a full copy of the node graph every time it starts, there must be a better
+  //        way.
   backend.SetViewerNode(viewer_);
   backend.SetVideoParams(video_params_);
   backend.SetAudioParams(audio_params_);
   backend.SetVideoDownloadMatrix(mat);
 
-  // Get hashes for each frame and group likes together
-  QMap< QByteArray, QLinkedList<rational> > times_to_render;
-
-  {
-    QList<rational> times = viewer_->video_frame_cache()->GetFrameListFromTimeRange(range_to_cache);
-
-    QFuture<QList<QByteArray> > hash_future = backend.Hash(times);
-    QList<QByteArray> hashes = hash_future.result();
-
-    // Determine any duplicates
-    int index = 0;
-    foreach (const QByteArray& hash, hashes) {
-      const rational& time = times.at(index);
-
-      if (use_disk_cache
-          && QFileInfo::exists(viewer_->video_frame_cache()->CachePathName(hash, video_params_.format()))) {
-        // Already exists, no need to render it again
-        FrameDownloaded(hash, {time});
-      } else {
-        times_to_render[hash].append(time);
-      }
-
-      index++;
-    }
-  }
-
-  // Render all frames necessary
-  QLinkedList<HashFrameFuturePair> render_lookup_table;
-  {
-    QLinkedList<HashTimePair> sorted_times;
-    QLinkedList<HashTimePair>::iterator sorted_iterator;
-
-    // Rendering is more efficient if we cache in order, so here we sort
-    QMap< QByteArray, QLinkedList<rational> >::const_iterator i;
-    for (i=times_to_render.constBegin(); i!=times_to_render.constEnd(); i++) {
-      const QByteArray& hash = i.key();
-      const rational& time = i.value().first();
-
-      bool inserted = false;
-
-      for (sorted_iterator=sorted_times.begin(); sorted_iterator!=sorted_times.end(); sorted_iterator++) {
-        if (sorted_iterator->time > time) {
-          sorted_times.insert(sorted_iterator, {time, hash});
-          inserted = true;
-          break;
-        }
-      }
-
-      if (!inserted) {
-        sorted_times.append({time, hash});
-      }
-    }
-
-    foreach (const HashTimePair& p, sorted_times) {
-      render_lookup_table.append({p.hash, backend.RenderFrame(p.time)});
-    }
-  }
-
   QLinkedList<RangeSampleFuturePair> audio_lookup_table;
-  if (audio_enabled) {
-    foreach (const TimeRange& r, range_to_cache) {
+  if (!audio_range.isEmpty()) {
+    foreach (const TimeRange& r, audio_range) {
       QList<TimeRange> ranges = RenderBackend::SplitRangeIntoChunks(r);
 
       foreach (const TimeRange& split, ranges) {
@@ -140,6 +84,66 @@ void RenderTask::Render(const TimeRangeList& range_to_cache,
     }
   }
 
+  // Get hashes for each frame and group likes together
+  QMap< QByteArray, QLinkedList<rational> > times_to_render;
+  QLinkedList<HashFrameFuturePair> render_lookup_table;
+  if (!video_range.isEmpty()) {
+
+    {
+      QList<rational> times = viewer_->video_frame_cache()->GetFrameListFromTimeRange(video_range);
+
+      QFuture<QList<QByteArray> > hash_future = backend.Hash(times);
+      QList<QByteArray> hashes = hash_future.result();
+
+      // Determine any duplicates
+      int index = 0;
+      foreach (const QByteArray& hash, hashes) {
+        const rational& time = times.at(index);
+
+        if (use_disk_cache
+            && QFileInfo::exists(viewer_->video_frame_cache()->CachePathName(hash, video_params_.format()))) {
+          // Already exists, no need to render it again
+          FrameDownloaded(hash, {time});
+        } else {
+          times_to_render[hash].append(time);
+        }
+
+        index++;
+      }
+    }
+
+    // Render all frames necessary
+    {
+      QLinkedList<HashTimePair> sorted_times;
+      QLinkedList<HashTimePair>::iterator sorted_iterator;
+
+      // Rendering is more efficient if we cache in order, so here we sort
+      QMap< QByteArray, QLinkedList<rational> >::const_iterator i;
+      for (i=times_to_render.constBegin(); i!=times_to_render.constEnd(); i++) {
+        const QByteArray& hash = i.key();
+        const rational& time = i.value().first();
+
+        bool inserted = false;
+
+        for (sorted_iterator=sorted_times.begin(); sorted_iterator!=sorted_times.end(); sorted_iterator++) {
+          if (sorted_iterator->time > time) {
+            sorted_times.insert(sorted_iterator, {time, hash});
+            inserted = true;
+            break;
+          }
+        }
+
+        if (!inserted) {
+          sorted_times.append({time, hash});
+        }
+      }
+
+      foreach (const HashTimePair& p, sorted_times) {
+        render_lookup_table.append({p.hash, backend.RenderFrame(p.time)});
+      }
+    }
+  }
+
   // Start downloading frames that have finished
 
   int counter = 0;
@@ -159,7 +163,7 @@ void RenderTask::Render(const TimeRangeList& range_to_cache,
 
     i = render_lookup_table.begin();
 
-    while (i != render_lookup_table.end()) {
+    while (!IsCancelled() && i != render_lookup_table.end()) {
       if (i->frame_future->IsFinished()) {
         FramePtr f = i->frame_future->Get().value<FramePtr>();
 
@@ -174,7 +178,7 @@ void RenderTask::Render(const TimeRangeList& range_to_cache,
 
     j = download_futures.begin();
 
-    while (j != download_futures.end()) {
+    while (!IsCancelled() && j != download_futures.end()) {
       if (j->download_future.isFinished()) {
         // Place it in the cache
         FrameDownloaded(j->hash, times_to_render.value(j->hash));
@@ -189,26 +193,20 @@ void RenderTask::Render(const TimeRangeList& range_to_cache,
       }
     }
 
-    if (audio_enabled) {
-      k = audio_lookup_table.begin();
+    k = audio_lookup_table.begin();
 
-      while (k != audio_lookup_table.end()) {
-        if (k->sample_future->IsFinished()) {
-          AudioDownloaded(k->range, k->sample_future->Get().value<SampleBufferPtr>());
+    while (!IsCancelled() && k != audio_lookup_table.end()) {
+      if (k->sample_future->IsFinished()) {
+        AudioDownloaded(k->range, k->sample_future->Get().value<SampleBufferPtr>());
 
-          k = audio_lookup_table.erase(k);
-        } else {
-          k++;
-        }
+        k = audio_lookup_table.erase(k);
+      } else {
+        k++;
       }
     }
   }
 }
 
-void RenderTask::AudioDownloaded(const TimeRange &, SampleBufferPtr)
-{
-}
-
 void RenderTask::SetAnchorPoint(const rational &r)
 {
   anchor_point_ = r;
diff --git a/app/task/render/render.h b/app/task/render/render.h
index d7407c97e..8f525f14b 100644
--- a/app/task/render/render.h
+++ b/app/task/render/render.h
@@ -34,13 +34,16 @@ public:
   RenderTask(ViewerOutput* viewer, const VideoRenderingParams &vparams, const AudioRenderingParams &aparams);
 
 protected:
-  void Render(const TimeRangeList &range_to_cache, const QMatrix4x4 &mat, bool audio_enabled, bool use_disk_cache);
+  void Render(const TimeRangeList &video_range,
+              const TimeRangeList &audio_range,
+              const QMatrix4x4 &mat,
+              bool use_disk_cache);
 
   virtual QFuture<void> DownloadFrame(FramePtr frame, const QByteArray &hash) = 0;
 
   virtual void FrameDownloaded(const QByteArray& hash, const QLinkedList<rational>& times) = 0;
 
-  virtual void AudioDownloaded(const TimeRange& range, SampleBufferPtr samples);
+  virtual void AudioDownloaded(const TimeRange& range, SampleBufferPtr samples) = 0;
 
   ViewerOutput* viewer() const
   {