diff --git a/build.gradle b/build.gradle
index 8565ca426..13a1cc44a 100644
--- a/build.gradle
+++ b/build.gradle
@@ -29,8 +29,8 @@ subprojects {
     group = 'com.skcraft'
     version = '4.3-SNAPSHOT'
 
-    sourceCompatibility = 1.6
-    targetCompatibility = 1.6
+    sourceCompatibility = 1.8
+    targetCompatibility = 1.8
 
     repositories {
         mavenCentral()
diff --git a/launcher-builder/src/main/java/com/skcraft/launcher/builder/ClientFileCollector.java b/launcher-builder/src/main/java/com/skcraft/launcher/builder/ClientFileCollector.java
index 02805a341..af947d7e6 100644
--- a/launcher-builder/src/main/java/com/skcraft/launcher/builder/ClientFileCollector.java
+++ b/launcher-builder/src/main/java/com/skcraft/launcher/builder/ClientFileCollector.java
@@ -12,12 +12,18 @@
 import com.skcraft.launcher.model.modpack.FileInstall;
 import com.skcraft.launcher.model.modpack.Manifest;
 import lombok.NonNull;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
 import lombok.extern.java.Log;
 import org.apache.commons.io.FilenameUtils;
 
 import java.io.File;
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.logging.Level;
 
 /**
  * Walks a path and adds hashed path versions to the given
@@ -51,13 +57,41 @@ public ClientFileCollector(@NonNull Manifest manifest, @NonNull PropertiesApplic
     protected DirectoryBehavior getBehavior(@NonNull String name) {
         return getDirectoryBehavior(name);
     }
+    
+    @AllArgsConstructor
+    @EqualsAndHashCode
+    private static class FileEntry {
+    	final File file;
+    	final String relPath;
+    }
+    
+    private final ArrayList<FileEntry> fileEntries = new ArrayList<>();
 
     @Override
     protected void onFile(File file, String relPath) throws IOException {
         if (file.getName().endsWith(FileInfoScanner.FILE_SUFFIX) || file.getName().endsWith(URL_FILE_SUFFIX)) {
             return;
         }
-
+        fileEntries.add(new FileEntry(file, relPath));
+    }
+    
+    @Override
+    protected void onWalkComplete() {
+    	long start = System.currentTimeMillis();
+    	fileEntries.parallelStream().forEach(fileEntry -> {
+    		try {
+				addFile(fileEntry.file, fileEntry.relPath);
+			} catch (IOException e) {
+				log.log(Level.SEVERE, "Error processing file.", e);
+				throw new RuntimeException(e);
+			}
+    	});
+    	long stop = System.currentTimeMillis();
+    	log.info("Finished processing " + fileEntries.size() + " files in " + (stop - start) + "ms.");
+    	fileEntries.clear();
+    }
+    
+    private void addFile(File file, String relPath) throws IOException {
         FileInstall entry = new FileInstall();
         String hash = Files.hash(file, hf).toString();
         String to = FilenameUtils.separatorsToUnix(FilenameUtils.normalize(relPath));
diff --git a/launcher-builder/src/main/java/com/skcraft/launcher/builder/DirectoryWalker.java b/launcher-builder/src/main/java/com/skcraft/launcher/builder/DirectoryWalker.java
index f92726cdc..442238f81 100644
--- a/launcher-builder/src/main/java/com/skcraft/launcher/builder/DirectoryWalker.java
+++ b/launcher-builder/src/main/java/com/skcraft/launcher/builder/DirectoryWalker.java
@@ -7,6 +7,7 @@
 package com.skcraft.launcher.builder;
 
 import lombok.NonNull;
+import lombok.extern.java.Log;
 
 import java.io.File;
 import java.io.IOException;
@@ -16,6 +17,7 @@
  * path (which may be modified by dropping certain directory entries),
  * and call {@link #onFile(java.io.File, String)} with each file.
  */
+@Log
 public abstract class DirectoryWalker {
 
     public enum DirectoryBehavior {
@@ -40,7 +42,11 @@ public enum DirectoryBehavior {
      * @throws IOException thrown on I/O error
      */
     public final void walk(@NonNull File dir) throws IOException {
-        walk(dir, "");
+        long start = System.currentTimeMillis();
+    	walk(dir, "");
+        long stop = System.currentTimeMillis();
+        log.info("Directory walk complete in " + (stop - start) + "ms.");
+        this.onWalkComplete();
     }
 
     /**
@@ -80,7 +86,7 @@ private void walk(@NonNull File dir, @NonNull String basePath) throws IOExceptio
      * Return the behavior for the given directory name.
      *
      * @param name the directory name
-     * @return the behavor
+     * @return the behavior
      */
     protected DirectoryBehavior getBehavior(String name) {
         return DirectoryBehavior.CONTINUE;
@@ -96,4 +102,8 @@ protected DirectoryBehavior getBehavior(String name) {
     protected abstract void onFile(File file, String relPath) throws IOException;
 
 
+    /**
+     * Called after the walk is completed.
+     */
+    protected void onWalkComplete() {};
 }
diff --git a/launcher/src/main/java/com/skcraft/launcher/model/modpack/Manifest.java b/launcher/src/main/java/com/skcraft/launcher/model/modpack/Manifest.java
index cac0f7f88..b3f46e5d6 100644
--- a/launcher/src/main/java/com/skcraft/launcher/model/modpack/Manifest.java
+++ b/launcher/src/main/java/com/skcraft/launcher/model/modpack/Manifest.java
@@ -22,6 +22,7 @@
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 @Data
@@ -39,7 +40,7 @@ public class Manifest extends BaseManifest {
     private LaunchModifier launchModifier;
     private List<Feature> features = new ArrayList<Feature>();
     @JsonManagedReference("manifest")
-    private List<ManifestEntry> tasks = new ArrayList<ManifestEntry>();
+    private List<ManifestEntry> tasks = Collections.synchronizedList(new ArrayList<ManifestEntry>());
     @Getter @Setter @JsonIgnore
     private Installer installer;
     private VersionManifest versionManifest;