diff --git a/pregelix/pregelix-dist/src/main/resources/conf/cluster.properties b/pregelix/pregelix-dist/src/main/resources/conf/cluster.properties
index f5d12a1..cac0aa5 100644
--- a/pregelix/pregelix-dist/src/main/resources/conf/cluster.properties
+++ b/pregelix/pregelix-dist/src/main/resources/conf/cluster.properties
@@ -40,11 +40,11 @@
 FRAME_SIZE=65536
 
 #CC JAVA_OPTS
-CCJAVA_OPTS="-Xmx1g -Djava.util.logging.config.file=logging.properties"
-# debug option: CCJAVA_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,address=7001,server=y,suspend=n -Xmx1g -Djava.util.logging.config.file=logging.properties"
+CCJAVA_OPTS="-Djava.util.logging.config.file=logging.properties"
+# debug option: CCJAVA_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,address=7001,server=y,suspend=n -Djava.util.logging.config.file=logging.properties"
 # Yourkit option: -agentpath:/grid/0/dev/vborkar/tools/yjp-10.0.4/bin/linux-x86-64/libyjpagent.so=port=20001"
 
 #NC JAVA_OPTS
-NCJAVA_OPTS="-Xmx1g -Djava.util.logging.config.file=logging.properties"
-# debug option: NCJAVA_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,address=7002,server=y,suspend=n -Xmx1g -Djava.util.logging.config.file=logging.properties"
+NCJAVA_OPTS="-Djava.util.logging.config.file=logging.properties"
+# debug option: NCJAVA_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,address=7002,server=y,suspend=n -Djava.util.logging.config.file=logging.properties"
 # Yourkit option: -agentpath:/grid/0/dev/vborkar/tools/yjp-10.0.4/bin/linux-x86-64/libyjpagent.so=port=20001"
diff --git a/pregelix/pregelix-dist/src/main/resources/scripts/startcc.sh b/pregelix/pregelix-dist/src/main/resources/scripts/startcc.sh
index d7a0ead..e637fde 100644
--- a/pregelix/pregelix-dist/src/main/resources/scripts/startcc.sh
+++ b/pregelix/pregelix-dist/src/main/resources/scripts/startcc.sh
@@ -49,7 +49,22 @@
 
 #Export JAVA_HOME and JAVA_OPTS
 export JAVA_HOME=$JAVA_HOME
-export JAVA_OPTS=$CCJAVA_OPTS
+
+#get the OS
+OS_NAME=`uname -a|awk '{print $1}'`
+LINUX_OS='Linux'
+
+if [ $OS_NAME = $LINUX_OS ];
+then
+        MEM_SIZE=`cat /proc/meminfo |grep MemTotal|awk '{print $2}'`
+else
+        MEM_SIZE=`sysctl -a | grep "hw.memsize ="|awk '{print $3}'`
+fi
+
+MEM_SIZE=$(($MEM_SIZE * 3 / 4))
+
+#Set JAVA_OPTS
+export JAVA_OPTS=$CCJAVA_OPTS" -Xmx"$MEM_SIZE
 
 PREGELIX_HOME=`pwd`
 
diff --git a/pregelix/pregelix-dist/src/main/resources/scripts/startnc.sh b/pregelix/pregelix-dist/src/main/resources/scripts/startnc.sh
index 6727bd5..ef9cfbe 100644
--- a/pregelix/pregelix-dist/src/main/resources/scripts/startnc.sh
+++ b/pregelix/pregelix-dist/src/main/resources/scripts/startnc.sh
@@ -68,13 +68,26 @@
 #Get node ID
 NODEID=`hostname | cut -d '.' -f 1`
 
-#Set JAVA_OPTS
-export JAVA_OPTS=$NCJAVA_OPTS
-
 PREGELIX_HOME=`pwd`
 
 #Enter the temp dir
 cd $NCTMP_DIR
 
+#get the OS
+OS_NAME=`uname -a|awk '{print $1}'`
+LINUX_OS='Linux'
+
+if [ $OS_NAME = $LINUX_OS ];
+then
+	MEM_SIZE=`cat /proc/meminfo |grep MemTotal|awk '{print $2}'`
+else
+	MEM_SIZE=`sysctl -a | grep "hw.memsize ="|awk '{print $3}'`
+fi
+
+MEM_SIZE=$(($MEM_SIZE * 3 / 4))
+
+#Set JAVA_OPTS
+export JAVA_OPTS=$NCJAVA_OPTS" -Xmx"$MEM_SIZE
+
 #Launch hyracks nc
 ${PREGELIX_HOME}/bin/pregelixnc -cc-host $CCHOST -cc-port $CC_CLUSTERPORT -cluster-net-ip-address $IPADDR  -data-ip-address $IPADDR -result-ip-address $IPADDR  -node-id $NODEID -iodevices "${IO_DIRS}" &> $NCLOGS_DIR/$NODEID.log &