diff --git a/trunk/src/app/srs_app_source.cpp b/trunk/src/app/srs_app_source.cpp
index 0e30be98c..287181244 100644
--- a/trunk/src/app/srs_app_source.cpp
+++ b/trunk/src/app/srs_app_source.cpp
@@ -182,7 +182,7 @@ void SrsMessageQueue::set_queue_size(double queue_size)
     queue_size_ms = (int)(queue_size * 1000);
 }
 
-int SrsMessageQueue::enqueue(SrsSharedPtrMessage* msg)
+int SrsMessageQueue::enqueue(SrsSharedPtrMessage* msg, bool* is_overflow)
 {
     int ret = ERROR_SUCCESS;
     
@@ -197,6 +197,11 @@ int SrsMessageQueue::enqueue(SrsSharedPtrMessage* msg)
     msgs.push_back(msg);
 
     while (av_end_time - av_start_time > queue_size_ms) {
+        // notice the caller queue already overflow and shrinked.
+        if (is_overflow) {
+            *is_overflow = true;
+        }
+        
         shrink();
     }
     
@@ -310,10 +315,23 @@ SrsConsumer::SrsConsumer(SrsSource* _source)
     mw_duration = 0;
     mw_waiting = false;
 #endif
+    
+#ifdef SRS_PERF_QUEUE_FAST_CACHE
+    mw_cache = new SrsMessageArray(SRS_PERF_MW_MSGS);
+    mw_count = 0;
+    mw_first_pkt = mw_last_pkt = 0;
+#endif
 }
 
 SrsConsumer::~SrsConsumer()
 {
+#ifdef SRS_PERF_QUEUE_FAST_CACHE
+    if (mw_cache) {
+        mw_cache->free(mw_count);
+        mw_count = 0;
+    }
+    srs_freep(mw_cache);
+#endif
     source->on_consumer_destroy(this);
     srs_freep(jitter);
     srs_freep(queue);
@@ -351,11 +369,37 @@ int SrsConsumer::enqueue(SrsSharedPtrMessage* __msg, bool atc, int tba, int tbv,
         }
     }
     
-    if ((ret = queue->enqueue(msg)) != ERROR_SUCCESS) {
+#ifdef SRS_PERF_QUEUE_FAST_CACHE
+    // use fast cache if available
+    if (mw_count < mw_cache->max) {
+        // update fast cache timestamps
+        if (mw_count == 0) {
+            mw_first_pkt = msg->timestamp;
+        }
+        mw_last_pkt = msg->timestamp;
+        
+        mw_cache->msgs[mw_count++] = msg;
+    } else{
+        // fast cache is full, use queue.
+        bool is_overflow = false;
+        if ((ret = queue->enqueue(msg, &is_overflow)) != ERROR_SUCCESS) {
+            return ret;
+        }
+        // when overflow, clear cache and refresh the fast cache.
+        if (is_overflow) {
+            mw_cache->free(mw_count);
+            if ((ret = dumps_queue_to_fast_cache()) != ERROR_SUCCESS) {
+                return ret;
+            }
+        }
+    }
+#else
+    if ((ret = queue->enqueue(msg, NULL)) != ERROR_SUCCESS) {
         return ret;
     }
+#endif
     
-    #ifdef SRS_PERF_QUEUE_COND_WAIT
+#ifdef SRS_PERF_QUEUE_COND_WAIT
     // fire the mw when msgs is enough.
     if (mw_waiting) {
         int duration_ms = queue->duration();
@@ -367,7 +411,7 @@ int SrsConsumer::enqueue(SrsSharedPtrMessage* __msg, bool atc, int tba, int tbv,
             mw_waiting = false;
         }
     }
-    #endif
+#endif
     
     return ret;
 }
@@ -388,12 +432,30 @@ int SrsConsumer::dump_packets(SrsMessageArray* msgs, int& count)
         return ret;
     }
     
+#ifdef SRS_PERF_QUEUE_FAST_CACHE
+    // only dumps an whole array to msgs.
+    for (int i = 0; i < mw_count; i++) {
+        msgs->msgs[i] = mw_cache->msgs[i];
+    }
+    count = mw_count;
+    
+    // when fast cache is not filled, 
+    // we donot check the queue, direclty zero fast cache.
+    if (mw_count < mw_cache->max) {
+        mw_count = 0;
+        mw_first_pkt = mw_last_pkt = 0;
+        return ret;
+    }
+    
+    return dumps_queue_to_fast_cache();
+#else
     // pump msgs from queue.
     if ((ret = queue->dump_packets(msgs->max, msgs->msgs, count)) != ERROR_SUCCESS) {
         return ret;
     }
     
     return ret;
+#endif
 }
 
 #ifdef SRS_PERF_QUEUE_COND_WAIT
@@ -402,6 +464,18 @@ void SrsConsumer::wait(int nb_msgs, int duration)
     mw_min_msgs = nb_msgs;
     mw_duration = duration;
     
+#ifdef SRS_PERF_QUEUE_FAST_CACHE
+    // when fast cache not overflow, always flush.
+    // so we donot care about the queue.
+    bool fast_cache_overflow = mw_count >= mw_cache->max;
+    int duration_ms = (int)(mw_last_pkt - mw_first_pkt);
+    bool match_min_msgs = mw_count > mw_min_msgs;
+    
+    // when fast cache overflow, or duration ok, signal to flush.
+    if (fast_cache_overflow || (match_min_msgs && duration_ms > mw_duration)) {
+        return;
+    }
+#else
     int duration_ms = queue->duration();
     bool match_min_msgs = queue->size() > mw_min_msgs;
     
@@ -409,6 +483,7 @@ void SrsConsumer::wait(int nb_msgs, int duration)
     if (match_min_msgs && duration_ms > mw_duration) {
         return;
     }
+#endif
     
     // the enqueue will notify this cond.
     mw_waiting = true;
@@ -427,6 +502,28 @@ int SrsConsumer::on_play_client_pause(bool is_pause)
     return ret;
 }
 
+#ifdef SRS_PERF_QUEUE_FAST_CACHE
+int SrsConsumer::dumps_queue_to_fast_cache()
+{
+    int ret =ERROR_SUCCESS;
+    
+    // fill fast cache with queue.
+    if ((ret = queue->dump_packets(mw_cache->max, mw_cache->msgs, mw_count)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    // set the timestamp when got message.
+    if (mw_count > 0) {
+        SrsSharedPtrMessage* first_msg = mw_cache->msgs[0];
+        mw_first_pkt = first_msg->timestamp;
+        
+        SrsSharedPtrMessage* last_msg = mw_cache->msgs[mw_count - 1];
+        mw_last_pkt = last_msg->timestamp;
+    }
+    
+    return ret;
+}
+#endif
+
 SrsGopCache::SrsGopCache()
 {
     cached_video_count = 0;
diff --git a/trunk/src/app/srs_app_source.hpp b/trunk/src/app/srs_app_source.hpp
index 68893de62..d1746c0ff 100644
--- a/trunk/src/app/srs_app_source.hpp
+++ b/trunk/src/app/srs_app_source.hpp
@@ -134,8 +134,9 @@ public:
     /**
     * enqueue the message, the timestamp always monotonically.
     * @param msg, the msg to enqueue, user never free it whatever the return code.
+    * @param is_overflow, whether overflow and shrinked. NULL to ignore.
     */
-    virtual int enqueue(SrsSharedPtrMessage* msg);
+    virtual int enqueue(SrsSharedPtrMessage* msg, bool* is_overflow = NULL);
     /**
     * get packets in consumer queue.
     * @pmsgs SrsSharedPtrMessage*[], used to store the msgs, user must alloc it.
@@ -172,6 +173,16 @@ private:
     int mw_min_msgs;
     int mw_duration;
 #endif
+#ifdef SRS_PERF_QUEUE_FAST_CACHE
+    // use fast cache for msgs
+    // @see https://github.com/winlinvip/simple-rtmp-server/issues/251
+    SrsMessageArray* mw_cache;
+    // the count of msg in fast cache.
+    int mw_count;
+    // the packet time in fast cache.
+    int64_t mw_first_pkt;
+    int64_t mw_last_pkt;
+#endif
 public:
     SrsConsumer(SrsSource* _source);
     virtual ~SrsConsumer();
@@ -219,6 +230,14 @@ public:
     * when client send the pause message.
     */
     virtual int on_play_client_pause(bool is_pause);
+private:
+#ifdef SRS_PERF_QUEUE_FAST_CACHE
+    /**
+    * dumps the queue to fast cache, 
+    * when fast cache is clear or queue is overflow.
+    */
+    virtual int dumps_queue_to_fast_cache();
+#endif
 };
 
 /**
diff --git a/trunk/src/core/srs_core.hpp b/trunk/src/core/srs_core.hpp
index ddf9b0d4f..9c6a2092d 100644
--- a/trunk/src/core/srs_core.hpp
+++ b/trunk/src/core/srs_core.hpp
@@ -31,7 +31,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 // current release version
 #define VERSION_MAJOR       2
 #define VERSION_MINOR       0
-#define VERSION_REVISION    64
+#define VERSION_REVISION    65
 // server info.
 #define RTMP_SIG_SRS_KEY "SRS"
 #define RTMP_SIG_SRS_ROLE "origin/edge server"
diff --git a/trunk/src/core/srs_core_performance.hpp b/trunk/src/core/srs_core_performance.hpp
index 9bb640965..ffb4788d5 100644
--- a/trunk/src/core/srs_core_performance.hpp
+++ b/trunk/src/core/srs_core_performance.hpp
@@ -128,6 +128,13 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 #undef SRS_PERF_MW_SO_RCVBUF
 /**
+* whether enable the fast cache.
+* @remark this improve performance for large connectios.
+* @remark this also introduce complex, default to disable it.
+* @see https://github.com/winlinvip/simple-rtmp-server/issues/251
+*/
+#undef SRS_PERF_QUEUE_FAST_CACHE
+/**
 * whether use cond wait to send messages.
 * @remark this improve performance for large connectios.
 * @see https://github.com/winlinvip/simple-rtmp-server/issues/251