diff --git a/indra/newview/app_settings/settings.xml b/indra/newview/app_settings/settings.xml
index b2e3c8b683..93cc605be0 100755
--- a/indra/newview/app_settings/settings.xml
+++ b/indra/newview/app_settings/settings.xml
@@ -721,6 +721,17 @@
       <integer>0</integer>
     </map>
 
+    <key>BackDistanceFactor</key>
+    <map>
+      <key>Comment</key>
+      <string>Keep invisible objects in memory which are in the distance range (the factor * draw_distance) to the camera</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>F32</string>
+      <key>Value</key>
+      <real>0.125</real>
+    </map>
     <key>BackgroundYieldTime</key>
     <map>
       <key>Comment</key>
@@ -732,6 +743,17 @@
       <key>Value</key>
       <integer>40</integer>
     </map>
+    <key>BackProjectionAngleSquared</key>
+    <map>
+      <key>Comment</key>
+      <string>squared tan(object bbox projection angle). that of invisible objects greater than this threshold are kept in memory</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>F32</string>
+      <key>Value</key>
+      <real>0.0311</real>
+    </map>
     <key>BottomPanelNew</key>
     <map>
       <key>Comment</key>
@@ -6306,6 +6328,17 @@
       <key>Value</key>
       <integer>64</integer>
     </map>
+    <key>NewObjectCreationThrottleDelayTime</key>
+    <map>
+      <key>Comment</key>
+      <string>time in seconds NewObjectCreationThrottle to take effect after the progress screen is lifted</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>F32</string>
+      <key>Value</key>
+      <real>2.0</real>
+    </map>
     <key>NextOwnerCopy</key>
     <map>
       <key>Comment</key>
diff --git a/indra/newview/llviewerregion.cpp b/indra/newview/llviewerregion.cpp
index da01c0406a..9c038d54d5 100755
--- a/indra/newview/llviewerregion.cpp
+++ b/indra/newview/llviewerregion.cpp
@@ -1233,6 +1233,7 @@ BOOL LLViewerRegion::idleUpdate(F32 max_update_time)
 void LLViewerRegion::calcNewObjectCreationThrottle()
 {
 	static LLCachedControl<S32> new_object_creation_throttle(gSavedSettings,"NewObjectCreationThrottle");
+	static LLCachedControl<F32> throttle_delay_time(gSavedSettings,"NewObjectCreationThrottleDelayTime");
 	static LLFrameTimer timer;
 
 	//
@@ -1243,16 +1244,20 @@ void LLViewerRegion::calcNewObjectCreationThrottle()
 	//>0: valid throttling number
 	//
 
-	if(gViewerWindow->getProgressView()->getVisible())
+	if(gViewerWindow->getProgressView()->getVisible() && throttle_delay_time > 0.f)
 	{
 		sNewObjectCreationThrottle = -2; //cancel the throttling
 		timer.reset();
 	}	
-	else if(sNewObjectCreationThrottle < 0) //just recoved from the login/teleport screen
+	else if(sNewObjectCreationThrottle < -1) //just recoved from the login/teleport screen
 	{
-		if(new_object_creation_throttle > 0 && timer.getElapsedTimeF32() > 2.0f) //wait for two seconds to reset the throttle
+		if(timer.getElapsedTimeF32() > throttle_delay_time) //wait for throttle_delay_time to reset the throttle
 		{
 			sNewObjectCreationThrottle = new_object_creation_throttle; //reset
+			if(sNewObjectCreationThrottle < -1)
+			{
+				sNewObjectCreationThrottle = -1;
+			}
 		}
 	}
 }
@@ -1285,6 +1290,8 @@ F32 LLViewerRegion::killInvisibleObjects(F32 max_time)
 	S32 update_counter = llmin(max_update, mImpl->mActiveSet.size());
 	LLVOCacheEntry::vocache_entry_set_t::iterator iter = mImpl->mActiveSet.upper_bound(mLastVisitedEntry);	
 	
+	LLVOCacheEntry::updateBackCullingFactors();
+
 	for(; update_counter > 0; --update_counter, ++iter)
 	{	
 		if(iter == mImpl->mActiveSet.end())
diff --git a/indra/newview/llvocache.cpp b/indra/newview/llvocache.cpp
index dcd1ae391d..1cfda038a8 100755
--- a/indra/newview/llvocache.cpp
+++ b/indra/newview/llvocache.cpp
@@ -33,7 +33,10 @@
 #include "lldrawable.h"
 #include "llviewerregion.h"
 #include "pipeline.h"
+#include "llagentcamera.h"
 
+F32 LLVOCacheEntry::sBackDistanceSquared = 0.f;
+F32 LLVOCacheEntry::sBackAngleTanSquared = 0.f;
 BOOL LLVOCachePartition::sNeedsOcclusionCheck = FALSE;
 LLTrace::MemStatHandle	LLVOCachePartition::sMemStat("LLVOCachePartition");
 
@@ -353,6 +356,21 @@ BOOL LLVOCacheEntry::writeToFile(LLAPRFile* apr_file) const
 	return success ;
 }
 
+//static 
+void LLVOCacheEntry::updateBackCullingFactors()
+{
+	//distance to keep objects = back_dist_factor * draw_distance
+	static LLCachedControl<F32> back_dist_factor(gSavedSettings,"BackDistanceFactor");
+
+	//squared tan(projection angle of the bbox), default is 10 (degree)
+	static LLCachedControl<F32> squared_back_angle(gSavedSettings,"BackProjectionAngleSquared");
+
+	sBackDistanceSquared = back_dist_factor * gAgentCamera.mDrawDistance;
+	sBackDistanceSquared *= sBackDistanceSquared;
+
+	sBackAngleTanSquared = squared_back_angle;
+}
+
 bool LLVOCacheEntry::isRecentlyVisible() const
 {
 	bool vis = LLViewerOctreeEntryData::isRecentlyVisible();
@@ -363,12 +381,10 @@ bool LLVOCacheEntry::isRecentlyVisible() const
 	}
 
 	//combination of projected area and squared distance
-	if(!vis && !mParentID && mSceneContrib > 0.0311f) //projection angle > 10 (degree)
+	if(!vis && !mParentID && mSceneContrib > sBackAngleTanSquared) 
 	{
-		//squared distance
-		const F32 SQUARED_CUT_OFF_DIST = 256.0; //16m
 		F32 rad = getBinRadius();
-		vis = (rad * rad / mSceneContrib < SQUARED_CUT_OFF_DIST);
+		vis = (rad * rad / mSceneContrib < sBackDistanceSquared);
 	}
 
 	return vis;
diff --git a/indra/newview/llvocache.h b/indra/newview/llvocache.h
index a385610a10..52b25b7f91 100755
--- a/indra/newview/llvocache.h
+++ b/indra/newview/llvocache.h
@@ -123,6 +123,8 @@ public:
 	void setUpdateFlags(U32 flags) {mUpdateFlags = flags;}
 	U32  getUpdateFlags() const    {return mUpdateFlags;}
 
+	static void updateBackCullingFactors();
+
 private:
 	static U32  getInvisibleObjectsLiveTime();
 
@@ -151,6 +153,9 @@ protected:
 	std::vector<LLVOCacheEntry*> mChildrenList; //children entries in a linked set.
 
 	BOOL                        mTouched; //if set, this entry is valid, otherwise it is invalid.
+
+	static F32                  sBackDistanceSquared;
+	static F32                  sBackAngleTanSquared;
 };
 
 class LLVOCachePartition : public LLViewerOctreePartition, public LLTrace::MemTrackable<LLVOCachePartition>