diff --git a/tools/perf.py b/tools/perf.py
index fdf830a77..67453ddeb 100755
--- a/tools/perf.py
+++ b/tools/perf.py
@@ -89,8 +89,10 @@ class PerfServer(object):
         else:
             server_command = [os.path.join(os.getcwd(), PerfTest.EXECUTABLE)]
         server_command.extend(['--', '-PD', '0'])
-        if (hasattr(test, "frames")):
-                server_command.extend(['-F', str(test.frames)])
+        if hasattr(test, "frames"):
+            server_command.extend(['-F', str(test.frames)])
+        if test.renderer != "software":
+            server_command.append('-N')
         subprocess.check_call(server_command)
         time.sleep(4)
         self.socket = socket.create_connection(self.address, timeout=1000)