diff --git a/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/map/hires/HiresTileModel.java b/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/map/hires/HiresTileModel.java
index 47d1f088..53de9ec1 100644
--- a/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/map/hires/HiresTileModel.java
+++ b/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/map/hires/HiresTileModel.java
@@ -32,6 +32,7 @@
 import de.bluecolored.bluemap.core.util.math.MatrixM4f;
 import de.bluecolored.bluemap.core.util.math.VectorM3f;
 
+import java.io.BufferedWriter;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
@@ -390,7 +391,7 @@ public void writeBufferGeometryJson(OutputStream out) throws IOException {
         sort();
 
         Gson gson = new GsonBuilder().create();
-        JsonWriter json = gson.newJsonWriter(new OutputStreamWriter(out, StandardCharsets.UTF_8));
+        JsonWriter json = gson.newJsonWriter(new BufferedWriter(new OutputStreamWriter(out, StandardCharsets.UTF_8), 81920));
 
         json.beginObject(); // main-object
 
diff --git a/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/Block.java b/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/Block.java
index 4d907d09..1a434e46 100644
--- a/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/Block.java
+++ b/BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/Block.java
@@ -32,7 +32,7 @@ public class Block<T extends Block<T>> {
 	private Chunk chunk;
 
 	private BlockState blockState;
-	private LightData lightData;
+	private final LightData lightData = new LightData(-1, -1);
 	private int biomeId;
 	
 	public Block(World world, int x, int y, int z) {
@@ -74,7 +74,7 @@ public T set(int x, int y, int z) {
 
 	protected void reset() {
 		this.blockState = null;
-		this.lightData = new LightData(-1, -1);
+		this.lightData.set(-1, -1);
 		this.biomeId = -1;
 	}
 
@@ -92,7 +92,7 @@ public T copy(Block<?> source) {
 		reset();
 
 		this.blockState = source.blockState;
-		this.lightData = new LightData(source.lightData.getSkyLight(), source.lightData.getBlockLight());
+		this.lightData.set(source.lightData.getSkyLight(), source.lightData.getBlockLight());
 		this.biomeId = source.biomeId;
 
 		return self();