diff --git a/processing/src/main/java/io/druid/query/topn/PooledTopNAlgorithm.java b/processing/src/main/java/io/druid/query/topn/PooledTopNAlgorithm.java
index 56e4c0fef4a..6c7fb11461a 100644
--- a/processing/src/main/java/io/druid/query/topn/PooledTopNAlgorithm.java
+++ b/processing/src/main/java/io/druid/query/topn/PooledTopNAlgorithm.java
@@ -40,7 +40,7 @@ public class PooledTopNAlgorithm
   private final Capabilities capabilities;
   private final TopNQuery query;
   private final StupidPool<ByteBuffer> bufferPool;
-  private static final int UNROLL_COUNT = 8; // Must be able to fit loop below
+  private static final int AGG_UNROLL_COUNT = 8; // Must be able to fit loop below
 
   public PooledTopNAlgorithm(
       Capabilities capabilities,
@@ -165,59 +165,80 @@ public class PooledTopNAlgorithm
       offset += aggregatorSizes[j];
     }
 
-    final int nAggregators = theAggregators.length;
-    final int extra = nAggregators % UNROLL_COUNT;
+    final int aggSize = theAggregators.length;
+    final int aggExtra = aggSize % AGG_UNROLL_COUNT;
 
     while (!cursor.isDone()) {
       final IndexedInts dimValues = dimSelector.getRow();
 
-      final int size = dimValues.size();
-      for (int i = 0; i < size; ++i) {
-        final int dimIndex = dimValues.get(i);
-        int position = positions[dimIndex];
-        if (SKIP_POSITION_VALUE == position) {
-          continue;
-        }
-        if (INIT_POSITION_VALUE == position) {
-          positions[dimIndex] = (dimIndex - numProcessed) * numBytesPerRecord;
-          position = positions[dimIndex];
-          for (int j = 0; j < nAggregators; ++j) {
-            theAggregators[j].init(resultsBuf, position + aggregatorOffsets[j]);
-          }
-          position = positions[dimIndex];
-        }
-
-        switch(extra) {
-          case 7:
-            theAggregators[6].aggregate(resultsBuf, position + aggregatorOffsets[6]);
-          case 6:
-            theAggregators[5].aggregate(resultsBuf, position + aggregatorOffsets[5]);
-          case 5:
-            theAggregators[4].aggregate(resultsBuf, position + aggregatorOffsets[4]);
-          case 4:
-            theAggregators[3].aggregate(resultsBuf, position + aggregatorOffsets[3]);
-          case 3:
-            theAggregators[2].aggregate(resultsBuf, position + aggregatorOffsets[2]);
-          case 2:
-            theAggregators[1].aggregate(resultsBuf, position + aggregatorOffsets[1]);
-          case 1:
-            theAggregators[0].aggregate(resultsBuf, position + aggregatorOffsets[0]);
-        }
-        for (int j = extra; j < nAggregators; j += UNROLL_COUNT) {
-          theAggregators[j].aggregate(resultsBuf, position + aggregatorOffsets[j]);
-          theAggregators[j+1].aggregate(resultsBuf, position + aggregatorOffsets[j+1]);
-          theAggregators[j+2].aggregate(resultsBuf, position + aggregatorOffsets[j+2]);
-          theAggregators[j+3].aggregate(resultsBuf, position + aggregatorOffsets[j+3]);
-          theAggregators[j+4].aggregate(resultsBuf, position + aggregatorOffsets[j+4]);
-          theAggregators[j+5].aggregate(resultsBuf, position + aggregatorOffsets[j+5]);
-          theAggregators[j+6].aggregate(resultsBuf, position + aggregatorOffsets[j+6]);
-          theAggregators[j+7].aggregate(resultsBuf, position + aggregatorOffsets[j+7]);
-        }
+      final int dimSize = dimValues.size();
+      final int dimExtra = dimSize - dimSize % 4;
+      final int dimUpper = (dimSize / 4) * 4 - 1;
+      for (int i = 0; i < dimUpper; i += 4) {
+        aggregateDimValues(positions, theAggregators, numProcessed, resultsBuf, numBytesPerRecord, aggregatorOffsets, aggSize, aggExtra, dimValues.get(i));
+        aggregateDimValues(positions, theAggregators, numProcessed, resultsBuf, numBytesPerRecord, aggregatorOffsets, aggSize, aggExtra, dimValues.get(i+1));
+        aggregateDimValues(positions, theAggregators, numProcessed, resultsBuf, numBytesPerRecord, aggregatorOffsets, aggSize, aggExtra, dimValues.get(i+2));
+        aggregateDimValues(positions, theAggregators, numProcessed, resultsBuf, numBytesPerRecord, aggregatorOffsets, aggSize, aggExtra, dimValues.get(i+3));
+      }
+      for (int i = dimExtra; i < dimSize; ++i) {
+        aggregateDimValues(positions, theAggregators, numProcessed, resultsBuf, numBytesPerRecord, aggregatorOffsets, aggSize, aggExtra, dimValues.get(i));
       }
       cursor.advance();
     }
   }
 
+  private static void aggregateDimValues(
+      int[] positions,
+      BufferAggregator[] theAggregators,
+      int numProcessed,
+      ByteBuffer resultsBuf,
+      int numBytesPerRecord,
+      int[] aggregatorOffsets,
+      int aggSize,
+      int aggExtra,
+      int dimIndex
+  )
+  {
+    if (SKIP_POSITION_VALUE == positions[dimIndex]) {
+      return;
+    }
+    if (INIT_POSITION_VALUE == positions[dimIndex]) {
+      positions[dimIndex] = (dimIndex - numProcessed) * numBytesPerRecord;
+      final int pos = positions[dimIndex];
+      for (int j = 0; j < aggSize; ++j) {
+        theAggregators[j].init(resultsBuf, pos + aggregatorOffsets[j]);
+      }
+    }
+    final int position = positions[dimIndex];
+
+    switch(aggExtra) {
+      case 7:
+        theAggregators[6].aggregate(resultsBuf, position + aggregatorOffsets[6]);
+      case 6:
+        theAggregators[5].aggregate(resultsBuf, position + aggregatorOffsets[5]);
+      case 5:
+        theAggregators[4].aggregate(resultsBuf, position + aggregatorOffsets[4]);
+      case 4:
+        theAggregators[3].aggregate(resultsBuf, position + aggregatorOffsets[3]);
+      case 3:
+        theAggregators[2].aggregate(resultsBuf, position + aggregatorOffsets[2]);
+      case 2:
+        theAggregators[1].aggregate(resultsBuf, position + aggregatorOffsets[1]);
+      case 1:
+        theAggregators[0].aggregate(resultsBuf, position + aggregatorOffsets[0]);
+    }
+    for (int j = aggExtra; j < aggSize; j += AGG_UNROLL_COUNT) {
+      theAggregators[j].aggregate(resultsBuf, position + aggregatorOffsets[j]);
+      theAggregators[j+1].aggregate(resultsBuf, position + aggregatorOffsets[j+1]);
+      theAggregators[j+2].aggregate(resultsBuf, position + aggregatorOffsets[j+2]);
+      theAggregators[j+3].aggregate(resultsBuf, position + aggregatorOffsets[j+3]);
+      theAggregators[j+4].aggregate(resultsBuf, position + aggregatorOffsets[j+4]);
+      theAggregators[j+5].aggregate(resultsBuf, position + aggregatorOffsets[j+5]);
+      theAggregators[j+6].aggregate(resultsBuf, position + aggregatorOffsets[j+6]);
+      theAggregators[j+7].aggregate(resultsBuf, position + aggregatorOffsets[j+7]);
+    }
+  }
+
   @Override
   protected void updateResults(
       PooledTopNParams params,