diff --git a/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java b/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
index c06e2545e..d9cf61bd9 100755
--- a/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
+++ b/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
@@ -553,8 +553,10 @@ public final class ChronicleMapBuilder<K, V> implements Cloneable,
 
     private int estimateSegmentsBasedOnSize() {
         // based on entries with multimap of 100 bytes.
-        int segmentsForEntries = estimateSegmentsForEntries();
-        return entrySize >= 100000
+        int segmentsForEntries = estimateSegmentsForEntries(entries);
+        return entrySize >= 1000000
+                ? segmentsForEntries * 16
+                : entrySize >= 100000
                 ? segmentsForEntries * 8
                 : entrySize >= 10000
                 ? segmentsForEntries * 4
@@ -563,8 +565,7 @@ public final class ChronicleMapBuilder<K, V> implements Cloneable,
                 : segmentsForEntries;
     }
 
-    private int estimateSegmentsForEntries() {
-        long size = entries;
+    private static int estimateSegmentsForEntries(long size) {
         if (size > 200 << 20)
             return 256;
         if (size >= 1 << 20)
@@ -575,6 +576,8 @@ public final class ChronicleMapBuilder<K, V> implements Cloneable,
             return 32;
         if (size >= 4 << 10)
             return 16;
+        if (size >= 1 << 10)
+            return 8;
         return 1;
     }
 
diff --git a/src/test/java/net/openhft/chronicle/map/LargeEntriesTest.java b/src/test/java/net/openhft/chronicle/map/LargeEntriesTest.java
index 6e4a4c01d..a732624a5 100644
--- a/src/test/java/net/openhft/chronicle/map/LargeEntriesTest.java
+++ b/src/test/java/net/openhft/chronicle/map/LargeEntriesTest.java
@@ -103,24 +103,25 @@ public class LargeEntriesTest {
     @Ignore("Performance Test")
     public void testLargeStringsPerf() throws ExecutionException, InterruptedException, IOException {
         doLargeEntryPerf(10000, 100 * 1024);
+        doLargeEntryPerf(1000000, 1024);
         doLargeEntryPerf(100000, 10 * 1024);
         doLargeEntryPerf(10000, 100 * 1024);
         doLargeEntryPerf(3000, 1024 * 1024);
     }
 
     private void doLargeEntryPerf(int ENTRIES, final int ENTRY_SIZE) throws IOException, InterruptedException, ExecutionException {
-        System.out.printf("Testing %,d entries of %,d KB%n", ENTRIES, ENTRY_SIZE);
+        System.out.printf("Testing %,d entries of %,d KB%n", ENTRIES, ENTRY_SIZE / 1024);
         File file = File.createTempFile("largeEntries", ".deleteme");
         file.deleteOnExit();
         final ChronicleMap<String, String> map = ChronicleMapBuilder
                 .of(String.class, String.class)
                 .valueMarshaller(SnappyStringMarshaller.INSTANCE)
-                .entries(ENTRIES * 2)
-                .entrySize(ENTRY_SIZE / 6)
+                .entries(ENTRIES)
+                .entrySize(ENTRY_SIZE / 7 + 200)
                 .putReturnsNull(true)
                 .createPersistedTo(file);
         {
-            warmUpCompression(ENTRY_SIZE);
+//            warmUpCompression(ENTRY_SIZE);
             int threads = Runtime.getRuntime().availableProcessors();
             ExecutorService es = Executors.newFixedThreadPool(threads);
             final int block = ENTRIES / threads;