diff --git a/sim_perf/run_spec.py b/sim_perf/run_spec.py
new file mode 100755
index 0000000..b066ae0
--- /dev/null
+++ b/sim_perf/run_spec.py
@@ -0,0 +1,73 @@
+#!/usr/bin/python
+
+import os
+import argparse
+import subprocess
+
+parser = argparse.ArgumentParser()
+parser.add_argument('--ff', dest = 'ff_insts', required = False, default = 40000000000)
+parser.add_argument('--sim', dest = 'sim_insts', required = False, default = 20000000000)
+parser.add_argument('--lat', dest = 'lat', required = True, help = 'load to use latency')
+parser.add_argument('--bbldir', dest = 'bbl_dir', required = True)
+parser.add_argument('--outdir', dest = 'out_dir', required = True)
+args = parser.parse_args()
+
+sim_bin = os.path.join(os.environ['RISCY_HOME'], 'sim_perf', 'build', 'sim')
+in_file = os.path.join(os.environ['RISCY_HOME'], 'sim_perf', 'in.txt')
+bbl_dir = os.path.abspath(args.bbl_dir)
+out_dir = os.path.abspath(args.out_dir)
+
+if not os.path.isdir(out_dir):
+    os.makedirs(out_dir)
+
+all_bench = [
+    '401.bzip2-source',
+    '401.bzip2-program',
+    '401.bzip2-combined',
+    '401.bzip2-chicken',
+    '401.bzip2-liberty',
+    '401.bzip2-text',
+    '403.gcc-166',
+    '403.gcc-200',
+    '403.gcc-c-typeck',
+    '403.gcc-cp-decl',
+    '403.gcc-expr',
+    '403.gcc-expr2',
+    '403.gcc-g23',
+    '403.gcc-s04',
+    '403.gcc-scilab',
+    '429.mcf',
+    '445.gobmk-13x13',
+    '445.gobmk-nngs',
+    '445.gobmk-score2',
+    '445.gobmk-trevorc',
+    '445.gobmk-trevord',
+    '456.hmmer-swiss41',
+    '456.hmmer-retro',
+    '458.sjeng',
+    '462.libquantum',
+    '464.h264ref-freb',
+    '464.h264ref-frem',
+    '464.h264ref-sem',
+    '471.omnetpp',
+    '473.astar-lakes',
+    '473.astar-rivers',
+    '483.xalancbmk',
+]
+
+for bench in all_bench:
+    cmd = ('screen -dmS ' + bench + '_lat' + str(args.lat) + ' bash -c \'' +
+           'cd ' + os.environ['RISCY_HOME'] + '; source setup.sh; ' +
+           sim_bin + ' BW' +
+           ' --ff ' + str(args.ff_insts) +
+           ' --sim ' + str(args.sim_insts) +
+           ' --out ' + os.path.join(out_dir, bench + '.perf') +
+           ' --lat ' + str(args.lat) +
+           ' -- ' + os.path.join(bbl_dir, 'bbl_spec_' + bench + '_ref') +
+           ' < ' + in_file +
+           ' &> ' + os.path.join(out_dir, bench + '.out\''))
+    if not os.path.isfile(os.path.join(bbl_dir, 'bbl_spec_' + bench + '_ref')):
+        raise Exception(bench + ' not found')
+    print cmd
+    subprocess.check_call(cmd, shell = True)
+