diff --git a/sims/vcs/run-coalperfs.sh b/sims/vcs/run-coalperfs.sh
old mode 100644
new mode 100755
index aaa5293c..b2ba82af
--- a/sims/vcs/run-coalperfs.sh
+++ b/sims/vcs/run-coalperfs.sh
@@ -1,13 +1,23 @@
 #!/bin/bash
 
+if [ $(basename "$PWD") != "vcs" ]
+then
+  echo "Run inside sims/vcs. Exiting."
+  exit 1
+fi
+
+set -ex
+
 configurations=("MemtraceCoreNV64B8IdConfig" "MemtraceCoreNV128B8IdConfig" "MemtraceCoreNV256B8IdConfig" "MemtraceCoreNV512B8IdConfig" "MemtraceCoreNV64B16IdConfig" "MemtraceCoreNV128B16IdConfig" "MemtraceCoreNV256B16IdConfig" "MemtraceCoreNV512B16IdConfig" "MemtraceCoreNV64B32IdConfig" "MemtraceCoreNV128B32IdConfig" "MemtraceCoreNV256B32IdConfig" "MemtraceCoreNV512B32IdConfig") 
 
 rm -f coal_perf.txt
-make clean
+# make clean
 
 for config in "${configurations[@]}"; do
-    time=$(make CONFIG="$config" run-binary-debug BINARY=none | grep "simulation time" | awk '{print $NF}')
+    make CONFIG="$config" run-binary BINARY=none
+    logfile="output/chipyard.TestHarness.$config/none.log"
+    time=$(grep "simulation time" "$logfile" | awk '{print $NF}')
     echo "($config, $time)" >> coal_perf.txt
 done
 
-cat coal_perf.txt
\ No newline at end of file
+cat coal_perf.txt