diff --git a/Minecraft.Client/LevelRenderer.cpp b/Minecraft.Client/LevelRenderer.cpp
index 9836007..7160ba5 100644
--- a/Minecraft.Client/LevelRenderer.cpp
+++ b/Minecraft.Client/LevelRenderer.cpp
@@ -1941,7 +1941,12 @@ bool LevelRenderer::updateDirtyChunks()
 						{
 							if( (!onlyRebuild) ||
 								globalChunkFlags[ pClipChunk->globalIdx ] & CHUNK_FLAG_COMPILED ||
+#ifdef _WINDOWS64
+								( distSq < 96 * 96 ) )	// Always rebuild really near things or else building (say) at tower up into empty blocks when we are low on memory will not create render data
+#else
 								( distSq < 20 * 20 ) )	// Always rebuild really near things or else building (say) at tower up into empty blocks when we are low on memory will not create render data
+#endif
+								
 							{
 								considered++;
 								// Is this chunk nearer than our nearest?
diff --git a/Minecraft.Client/LevelRenderer.h b/Minecraft.Client/LevelRenderer.h
index 41eb359..b3559e1 100644
--- a/Minecraft.Client/LevelRenderer.h
+++ b/Minecraft.Client/LevelRenderer.h
@@ -49,6 +49,8 @@ public:
 	static const int MAX_COMMANDBUFFER_ALLOCATIONS = 448 * 1024 * 1024;		// 4J - added - hard limit is 512 so giving a lot of headroom here for fragmentation (have seen 16MB lost to fragmentation in multiplayer crash dump before)
 #elif defined __PS3__
 	static const int MAX_COMMANDBUFFER_ALLOCATIONS = 110 * 1024 * 1024;		// 4J - added
+#elif defined _WINDOWS64
+	static const int MAX_COMMANDBUFFER_ALLOCATIONS = 2047 * 1024 * 1024;    // whisper - added (wow)
 #else
 	static const int MAX_COMMANDBUFFER_ALLOCATIONS = 55 * 1024 * 1024;		// 4J - added
 #endif