diff --git a/indra/newview/llface.cpp b/indra/newview/llface.cpp
index 9c0205765b..a7378b093c 100755
--- a/indra/newview/llface.cpp
+++ b/indra/newview/llface.cpp
@@ -166,6 +166,8 @@ void LLFace::init(LLDrawable* drawablep, LLViewerObject* objp)
 	mBoundingSphereRadius = 0.0f ;
 
 	mHasMedia = FALSE ;
+
+	mParticleGeneration = 0; // <FS:ND/> Default = no particle
 }
 
 void LLFace::destroy()
@@ -183,9 +185,14 @@ void LLFace::destroy()
 		}
 	}
 	
-	if (isState(LLFace::PARTICLE))
+	// <FS:ND> Make sure we released any allocated VB index if this was a particle
+	// if (isState(LLFace::PARTICLE))
+	if (isState(LLFace::PARTICLE) || mParticleGeneration )
+	// </FS:ND>
 	{
-		LLVOPartGroup::freeVBSlot(getGeomIndex()/4);
+		LLVOPartGroup::freeVBSlot(getGeomIndex()/4,mParticleGeneration);
+		mParticleGeneration = 0;
+
 		clearState(LLFace::PARTICLE);
 	}
 
@@ -414,8 +421,16 @@ void LLFace::setSize(S32 num_vertices, S32 num_indices, bool align)
 	llassert(verify());
 }
 
-void LLFace::setGeomIndex(U16 idx) 
+// <FS:ND> Pass another flag to mark this index as from LLVOPartGroup, in that case it needs to be freed with LLVOPartGroup::LLVOPartGroup
+// void LLFace::setGeomIndex(U16 idx) 
+void LLFace::setGeomIndex(U16 idx, U32 aParticleGeneration ) 
+// </FS:ND>
 { 
+	if( mParticleGeneration && mGeomIndex != idx )
+		LLVOPartGroup::freeVBSlot(getGeomIndex()/4,mParticleGeneration);
+	
+	mParticleGeneration = aParticleGeneration;
+
 	if (mGeomIndex != idx)
 	{
 		mGeomIndex = idx; 
diff --git a/indra/newview/llface.h b/indra/newview/llface.h
index d3a561facc..b780322823 100755
--- a/indra/newview/llface.h
+++ b/indra/newview/llface.h
@@ -207,7 +207,11 @@ public:
 	BOOL		verify(const U32* indices_array = NULL) const;
 	void		printDebugInfo() const;
 
-	void		setGeomIndex(U16 idx); 
+	// <FS:ND> Pass another flag to mark this index as from LLVOPartGroup, in that case it needs to be freed with LLVOPartGroup::LLVOPartGroup
+	// void		setGeomIndex(U16 idx); 
+	void		setGeomIndex(U16 idx, U32 aParticleGeneration = 0); 
+	// </FS:ND>
+
 	void		setIndicesIndex(S32 idx);
 	void		setDrawInfo(LLDrawInfo* draw_info);
 
@@ -359,6 +363,9 @@ public:
 				lhs->getTexture() < rhs->getTexture();
 		}
 	};
+
+private:
+	U32 mParticleGeneration;
 };
 
 #endif // LL_LLFACE_H
diff --git a/indra/newview/llviewerpartsim.cpp b/indra/newview/llviewerpartsim.cpp
index f7eb7df46c..73f85c161d 100755
--- a/indra/newview/llviewerpartsim.cpp
+++ b/indra/newview/llviewerpartsim.cpp
@@ -284,16 +284,36 @@ void LLViewerPartGroup::updateParticles(const F32 lastdt)
 	LLViewerCamera* camera = LLViewerCamera::getInstance();
 	LLViewerRegion *regionp = getRegion();
 	S32 end = (S32) mParticles.size();
-	for (S32 i = 0 ; i < (S32)mParticles.size();)
+
+	// <FS:ND> Instead of walking the current particles back to front, we first make a copy, then sort by adress and refill mParticles as needed.
+	mParticlesTemp.swap( mParticles );
+	mParticles.erase( mParticles.begin(), mParticles.end() );
+	std::sort( mParticlesTemp.begin(), mParticlesTemp.end() );
+
+	// for (S32 i = 0 ; i < (S32)mParticles.size(); )
+	for (S32 i = 0 ; i < (S32)mParticlesTemp.size(); ++i )
+	// </FS:ND>
 	{
-		LLVector3 a(0.f, 0.f, 0.f);
-		LLViewerPart* part = mParticles[i] ;
+		// LLVector3 a(0.f, 0.f, 0.f); // <FS:ND/> Unused
+		LLViewerPart* part = mParticlesTemp[i] ;
 
 		dt = lastdt + mSkippedTime - part->mSkipOffset;
 		part->mSkipOffset = 0.f;
 
 		// Update current time
 		const F32 cur_time = part->mLastUpdateTime + dt;
+
+		// <FS:ND> Bail out as soon as possible to avoid all the complicated work down.
+		if( cur_time > part->mMaxAge || LLViewerPart::LL_PART_DEAD_MASK == part->mFlags )
+		{
+			if (part->mVPCallback)
+				(*part->mVPCallback)(*part, dt);
+
+			delete part ;
+			continue;
+		}
+		// </FS:ND>
+
 		const F32 frac = cur_time / part->mMaxAge;
 
 		// "Drift" the object based on the source object
@@ -397,26 +417,34 @@ void LLViewerPartGroup::updateParticles(const F32 lastdt)
 		part->mLastUpdateTime = cur_time;
 
 
+		// <FS:ND> We did that above
 		// Kill dead particles (either flagged dead, or too old)
-		if ((part->mLastUpdateTime > part->mMaxAge) || (LLViewerPart::LL_PART_DEAD_MASK == part->mFlags))
-		{
-			mParticles[i] = mParticles.back() ;
-			mParticles.pop_back() ;
-			delete part ;
-		}
-		else 
+		// if ((part->mLastUpdateTime > part->mMaxAge) || (LLViewerPart::LL_PART_DEAD_MASK == part->mFlags))
+		// {
+		//	mParticles[i] = mParticles.back() ;
+		//	mParticles.pop_back() ;
+		//	delete part ;
+		// }
+		// else 
+		// </FS:ND>
 		{
 			F32 desired_size = calc_desired_size(camera, part->mPosAgent, part->mScale);
 			if (!posInGroup(part->mPosAgent, desired_size))
 			{
 				// Transfer particles between groups
 				LLViewerPartSim::getInstance()->put(part) ;
-				mParticles[i] = mParticles.back() ;
-				mParticles.pop_back() ;
+
+				// <FS:ND> No need for any transfer, just to not add to mParticles.
+				// mParticles[i] = mParticles.back() ;
+				// mParticles.pop_back() ;
+				// </FS:ND>
 			}
 			else
 			{
-				i++ ;
+				// <FS:ND> Keep current particle in this group.
+				// i++ ;
+				mParticles.push_back( part );
+				// </FS:ND>
 			}
 		}
 	}
@@ -892,3 +920,76 @@ void LLViewerPartSim::clearParticlesByOwnerID(const LLUUID& task_id)
 	}
 }
 
+// <FS:ND> Object pool for LLViewerPart
+U8 *sParts;
+U8 *sPartsEnd;
+U32 sFree[ LL_MAX_PARTICLE_COUNT/32 ];
+U32 sPartSize;
+
+S32 findFreeIndex()
+{
+	for( int i = 0; i < LL_MAX_PARTICLE_COUNT/32; ++i )
+	{
+		if( sFree[i]  )
+		{
+			U32 val = sFree[i];
+			U32 mask = 1;
+			int j(0);
+			for( j = 0; j < 32; ++j )
+			{
+				if( mask & val )
+				{
+					mask = ~mask;
+					break;
+				}
+
+				mask <<= 1;
+			}
+
+			sFree[ i ] = val & mask;
+			return i*32+j;
+		}
+	}
+	return -1;
+}
+
+void* LLViewerPart::operator new(size_t size)
+{
+	if( !sParts )
+	{
+		sPartSize = sizeof( LLViewerPart );
+		sPartSize += 0xF;
+		sPartSize &= ~0xF;
+		sParts = reinterpret_cast<U8*>( ll_aligned_malloc<16>( sPartSize * LL_MAX_PARTICLE_COUNT ) );
+		for( int i = 0; i < LL_MAX_PARTICLE_COUNT/32; ++i )
+			sFree[ i ] = 0xFFFFFFFF;
+
+		sPartsEnd = sParts + sPartSize * LL_MAX_PARTICLE_COUNT;
+	}
+
+	S32 i = findFreeIndex();
+	if( i < 0 )
+		return new char[ size ];
+
+	return reinterpret_cast< void* >( sParts + sPartSize*i );
+}
+
+void LLViewerPart::operator delete(void* ptr)
+{
+	if( ptr < sParts || ptr >= sPartsEnd )
+	{
+		delete []  (char*)ptr;
+		return;
+	}
+
+	U32 diff = static_cast<U32>( reinterpret_cast<U8*>(ptr) - sParts );
+	diff /= sPartSize;
+
+	U32 i = (diff & ~0x0000001F) / 32;
+	U32 j =  diff &  0x0000001F;
+
+	U32 mask = 1 << j;
+
+	sFree[ i ] |= mask;
+}
+// </FS:ND>
diff --git a/indra/newview/llviewerpartsim.h b/indra/newview/llviewerpartsim.h
index 40e8e1d45d..501fe9b24b 100755
--- a/indra/newview/llviewerpartsim.h
+++ b/indra/newview/llviewerpartsim.h
@@ -81,6 +81,10 @@ public:
 
 
 	static U32		sNextPartID;
+	// <FS:ND> Object pool for LLViewerPart
+	void* operator new(size_t size);
+	void operator delete(void* ptr);
+	// </FS:ND>
 };
 
 
@@ -108,6 +112,7 @@ public:
 
 	typedef std::vector<LLViewerPart*>  part_list_t;
 	part_list_t mParticles;
+	part_list_t mParticlesTemp; // <FS:ND/> Temporary list for iteration in updateParticles
 
 	const LLVector3 &getCenterAgent() const		{ return mCenterAgent; }
 	S32 getCount() const					{ return (S32) mParticles.size(); }
diff --git a/indra/newview/llvopartgroup.cpp b/indra/newview/llvopartgroup.cpp
index f90d827827..27d54c58e5 100755
--- a/indra/newview/llvopartgroup.cpp
+++ b/indra/newview/llvopartgroup.cpp
@@ -50,6 +50,8 @@ extern U64MicrosecondsImplicit gFrameTime;
 
 LLPointer<LLVertexBuffer> LLVOPartGroup::sVB = NULL;
 S32 LLVOPartGroup::sVBSlotCursor = 0;
+U32 sFreeIndex[LL_MAX_PARTICLE_COUNT/32] = {0};
+U32 sIndexGeneration = 1;
 
 void LLVOPartGroup::initClass()
 {
@@ -59,6 +61,11 @@ void LLVOPartGroup::initClass()
 //static
 void LLVOPartGroup::restoreGL()
 {
+	sIndexGeneration += 2;
+
+	for( int i = 0; i < LL_MAX_PARTICLE_COUNT/32; ++i )
+		sFreeIndex[i] = 0xFFFFFFFF;
+
 
 	//TODO: optimize out binormal mask here.  Specular and normal coords as well.
 	sVB = new LLVertexBuffer(VERTEX_DATA_MASK | LLVertexBuffer::MAP_TANGENT | LLVertexBuffer::MAP_TEXCOORD1 | LLVertexBuffer::MAP_TEXCOORD2, GL_STREAM_DRAW_ARB);
@@ -118,12 +125,37 @@ void LLVOPartGroup::destroyGL()
 //static
 S32 LLVOPartGroup::findAvailableVBSlot()
 {
-	if (sVBSlotCursor >= LL_MAX_PARTICLE_COUNT)
-	{ //no more available slots
-		return -1;
+	for( int i = 0; i < LL_MAX_PARTICLE_COUNT/32; ++i )
+	{
+		if( sFreeIndex[i] != 0 )
+		{
+			U32 val = sFreeIndex[i];
+			U32 mask = 1;
+			int j(0);
+			for( j = 0; j < 32; ++j )
+			{
+				if( mask & val )
+				{
+					mask = ~mask;
+					break;
+				}
+
+				mask <<= 1;
+			}
+
+			sFreeIndex[ i ] = val & mask;
+			return i*32+j;
+		}
 	}
 
-	return sVBSlotCursor++;
+	return -1;
+
+//	if (sVBSlotCursor >= LL_MAX_PARTICLE_COUNT)
+//	{ //no more available slots
+//		return -1;
+//	}
+//
+//	return sVBSlotCursor++;
 }
 
 bool ll_is_part_idx_allocated(S32 idx, S32* start, S32* end)
@@ -142,7 +174,8 @@ bool ll_is_part_idx_allocated(S32 idx, S32* start, S32* end)
 }
 
 //static
-void LLVOPartGroup::freeVBSlot(S32 idx)
+// void LLVOPartGroup::freeVBSlot(S32 idx)
+void LLVOPartGroup::freeVBSlot(S32 idx, U32 generation )
 {
 	/*llassert(idx < LL_MAX_PARTICLE_COUNT && idx >= 0);
 	//llassert(sVBSlotCursor > sVBSlotFree);
@@ -153,6 +186,16 @@ void LLVOPartGroup::freeVBSlot(S32 idx)
 		sVBSlotCursor--;
 		*sVBSlotCursor = idx;
 	}*/
+
+	if( sIndexGeneration != generation || idx < 0 || idx >= LL_MAX_PARTICLE_COUNT )
+		return;
+
+	U32 i = (idx & ~0x0000001F) / 32;
+	U32 j =  idx &  0x0000001F;
+
+	U32 mask = 1 << j;
+
+	sFreeIndex[ i ] |= mask;
 }
 
 LLVOPartGroup::LLVOPartGroup(const LLUUID &id, const LLPCode pcode, LLViewerRegion *regionp)
@@ -869,7 +912,11 @@ void LLParticlePartition::getGeometry(LLSpatialGroup* group)
 			S32 idx = LLVOPartGroup::findAvailableVBSlot();
 			if (idx >= 0)
 			{
-				facep->setGeomIndex(idx*4);
+				// <FS:ND> Face needs to release the index when it gets destroyed.
+				// facep->setGeomIndex(idx*4);
+				facep->setGeomIndex(idx*4, sIndexGeneration);
+				// <FS:ND>
+
 				facep->setIndicesIndex(idx*6);
 				facep->setVertexBuffer(LLVOPartGroup::sVB);
 				facep->setPoolType(LLDrawPool::POOL_ALPHA);
diff --git a/indra/newview/llvopartgroup.h b/indra/newview/llvopartgroup.h
index 2ef8b1c848..e245a2bc16 100755
--- a/indra/newview/llvopartgroup.h
+++ b/indra/newview/llvopartgroup.h
@@ -48,7 +48,9 @@ public:
 	static void restoreGL();
 	static void destroyGL();
 	static S32 findAvailableVBSlot();
-	static void freeVBSlot(S32 idx);
+
+	// static void freeVBSlot(S32 idx);
+	static void freeVBSlot(S32 idx, U32 generation);
 
 	enum
 	{