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 &
diff --git a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/client/Client.java b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/client/Client.java
index 393c8c9..20435cd 100644
--- a/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/client/Client.java
+++ b/pregelix/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/client/Client.java
@@ -70,6 +70,9 @@
 
         @Option(name = "-ckp-interval", usage = "checkpointing interval -- for fault-tolerance", required = false)
         public int ckpInterval = -1;
+
+        @Option(name = "-dyn-opt", usage = "whether to enable dynamic optimization -- for better performance", required = false)
+        public boolean dynamicOptimization = false;
     }
 
     public static void run(String[] args, PregelixJob job) throws Exception {
@@ -121,6 +124,7 @@
     }
 
     private static void setJobSpecificSettings(PregelixJob job, Options options) {
+        job.setDynamicVertexValueSize(options.dynamicOptimization);
         job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, options.numVertices);
         job.getConfiguration().setLong(PregelixJob.NUM_EDGES, options.numEdges);
         job.getConfiguration().setLong(ShortestPathsVertex.SOURCE_ID, options.sourceId);
diff --git a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/jobgen/JobGenerator.java b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/jobgen/JobGenerator.java
index 0a5e891..c7eff1e 100644
--- a/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/jobgen/JobGenerator.java
+++ b/pregelix/pregelix-example/src/test/java/edu/uci/ics/pregelix/example/jobgen/JobGenerator.java
@@ -111,6 +111,7 @@
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH));
         job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
         job.getConfiguration().setLong(ShortestPathsVertex.SOURCE_ID, 0);
+        job.setDynamicVertexValueSize(true);
         job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
     }
 
@@ -216,6 +217,7 @@
         FileOutputFormat.setOutputPath(job, new Path(HDFS_OUTPUTPAH));
         job.getConfiguration().setLong(PregelixJob.NUM_VERTICE, 20);
         job.getConfiguration().setLong(ShortestPathsVertex.SOURCE_ID, 0);
+        job.setDynamicVertexValueSize(true);
         job.getConfiguration().writeXml(new FileOutputStream(new File(outputPath)));
     }
 
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/ShortestPaths.xml b/pregelix/pregelix-example/src/test/resources/jobs/ShortestPaths.xml
index 9acd7bc..87c35f7 100644
--- a/pregelix/pregelix-example/src/test/resources/jobs/ShortestPaths.xml
+++ b/pregelix/pregelix-example/src/test/resources/jobs/ShortestPaths.xml
@@ -128,6 +128,7 @@
 <property><name>pregelix.vertexInputFormatClass</name><value>edu.uci.ics.pregelix.example.PageRankVertex$SimulatedPageRankVertexInputFormat</value></property>
 <property><name>mapred.job.queue.name</name><value>default</value></property>
 <property><name>mapred.job.tracker.persist.jobstatus.active</name><value>false</value></property>
+<property><name>pregelix.incStateLength</name><value>true</value></property>
 <property><name>mapred.reduce.slowstart.completed.maps</name><value>0.05</value></property>
 <property><name>topology.script.number.args</name><value>100</value></property>
 <property><name>mapred.skip.map.max.skip.records</name><value>0</value></property>
diff --git a/pregelix/pregelix-example/src/test/resources/jobs/ShortestPathsReal.xml b/pregelix/pregelix-example/src/test/resources/jobs/ShortestPathsReal.xml
index 6c25575..b757514 100644
--- a/pregelix/pregelix-example/src/test/resources/jobs/ShortestPathsReal.xml
+++ b/pregelix/pregelix-example/src/test/resources/jobs/ShortestPathsReal.xml
@@ -128,6 +128,7 @@
 <property><name>pregelix.vertexInputFormatClass</name><value>edu.uci.ics.pregelix.example.inputformat.TextShortestPathsInputFormat</value></property>
 <property><name>mapred.job.queue.name</name><value>default</value></property>
 <property><name>mapred.job.tracker.persist.jobstatus.active</name><value>false</value></property>
+<property><name>pregelix.incStateLength</name><value>true</value></property>
 <property><name>mapred.reduce.slowstart.completed.maps</name><value>0.05</value></property>
 <property><name>topology.script.number.args</name><value>100</value></property>
 <property><name>mapred.skip.map.max.skip.records</name><value>0</value></property>