diff --git a/core/src/main/scala/spark/BoundedMemoryCache.scala b/core/src/main/scala/spark/BoundedMemoryCache.scala
index 10143d3dd22bb24ab2a05044facd84f5636cea70..6f2f92f6051f7701f621cee3419e1d853c44677c 100644
--- a/core/src/main/scala/spark/BoundedMemoryCache.scala
+++ b/core/src/main/scala/spark/BoundedMemoryCache.scala
@@ -46,7 +46,7 @@ class BoundedMemoryCache extends Cache with Logging {
 
   private def getMaxBytes(): Long = {
     val memoryFractionToUse = System.getProperty(
-      "spark.boundedMemoryCache.memoryFraction", "0.75").toDouble
+      "spark.boundedMemoryCache.memoryFraction", "0.66").toDouble
     (Runtime.getRuntime.totalMemory * memoryFractionToUse).toLong
   }
 
diff --git a/core/src/main/scala/spark/SparkEnv.scala b/core/src/main/scala/spark/SparkEnv.scala
index 81caf7cff05928ea8c653d57f2bfcfdac5132fe6..d37d1aa90912b2a4ae78da0c0dc5e6b9fa6e1fa1 100644
--- a/core/src/main/scala/spark/SparkEnv.scala
+++ b/core/src/main/scala/spark/SparkEnv.scala
@@ -21,7 +21,7 @@ object SparkEnv {
   }
 
   def createFromSystemProperties(isMaster: Boolean): SparkEnv = {
-    val cacheClass = System.getProperty("spark.cache.class", "spark.SoftReferenceCache")
+    val cacheClass = System.getProperty("spark.cache.class", "spark.BoundedMemoryCache")
     val cache = Class.forName(cacheClass).newInstance().asInstanceOf[Cache]
     
     val serializerClass = System.getProperty("spark.serializer", "spark.JavaSerializer")