diff --git a/run.py b/run.py
index 78a405bb..2440a700 100644
--- a/run.py
+++ b/run.py
@@ -102,7 +102,7 @@ def parse_args():
                         help='Max task to run in parallel on one GPU. '
                         'It will only be used in the local runner.',
                         type=int,
-                        default=32)
+                        default=1)
     parser.add_argument(
         '--retry',
         help='Number of retries if the job failed when using slurm or dlc. '