diff --git a/src/ch/zhaw/ads/ParallelQuickerSortServer.java b/src/ch/zhaw/ads/ParallelQuickerSortServer.java
index b6d9a44..0378875 100644
--- a/src/ch/zhaw/ads/ParallelQuickerSortServer.java
+++ b/src/ch/zhaw/ads/ParallelQuickerSortServer.java
@@ -26,14 +26,65 @@ public class ParallelQuickerSortServer extends Thread implements CommandExecutor
 
         if (left < right) {
             // TODO Aufgabe 12.3
+            mid = partition(arr, left, right);
+            if(mid - left > SPLIT_THRESHOLD) {
+                t1 = new ParallelQuickerSortServer(arr, left, mid - 1);
+                t1.start();
+            } else {
+                quickerSort(arr, left, mid - 1);
+            }
+            if(right - mid > SPLIT_THRESHOLD) {
+                t2 = new ParallelQuickerSortServer(arr, mid, right);
+                t2.start();
+            } else {
+                quickerSort(arr, mid, right);
+            }
+        }
+        if(t1 != null) {
+            try {
+                t1.join();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+        if(t2 != null) {
+            try {
+                t2.join();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
         }
     }
 
     private void quickerSort(int[] arr, int left, int right) {
+        if(arr.length <= 50) {
+            insertionSort(arr, left, right);
+        } else {
+            if(left < right) {
+                int mid = partition(arr, left, right);
+                quickerSort(arr, left, mid - 1);
+                quickerSort(arr, mid, right);
+            }
+        }
         // TODO Aus Aufgabe 12.1 übernehmen
     }
 
     private int partition(int[] arr, int left, int right) {
+        int pivot = arr[(left + right) / 2];
+        while(left <= right) {
+            while(arr[left] < pivot) {
+                left++;
+            }
+            while(arr[right] > pivot) {
+                right--;
+            }
+            if(left <= right) {
+                swap(arr, left, right);
+                left++;
+                right--;
+            }
+        }
+        return left;
         // TODO Aus Aufgabe 12.1 übernehmen
     }
 
diff --git a/src/ch/zhaw/ads/SortServer.java b/src/ch/zhaw/ads/SortServer.java
index d6f8d07..30a6d78 100644
--- a/src/ch/zhaw/ads/SortServer.java
+++ b/src/ch/zhaw/ads/SortServer.java
@@ -75,11 +75,35 @@ public class SortServer implements CommandExecutor {
     }
 
     private void quickerSort(int[] arr, int left, int right) {
-        // To do Aufgabe 12.1
+        if(arr.length <= 50) {
+            insertionSort(arr);
+        } else {
+            if(left < right) {
+                int mid = partition(arr, left, right);
+                quickerSort(arr, left, mid - 1);
+                quickerSort(arr, mid, right);
+            }
+        }
+        // Todo Aufgabe 12.1
     }
 
     private int partition (int[] arr, int left, int right) {
-        // To do Aufgabe 12.1
+        int pivot = arr[(left + right) / 2];
+        while(left <= right) {
+            while(arr[left] < pivot) {
+                left++;
+            }
+            while(arr[right] > pivot) {
+                right--;
+            }
+            if(left <= right) {
+                swap(arr, left, right);
+                left++;
+                right--;
+            }
+        }
+        return left;
+        // Todo Aufgabe 12.1
     }
 
     private boolean isSorted(int[] a) {