diff --git a/deepmd/pt/utils/env.py b/deepmd/pt/utils/env.py
index 9803f8d04d..0e1322a640 100644
--- a/deepmd/pt/utils/env.py
+++ b/deepmd/pt/utils/env.py
@@ -21,7 +21,7 @@
     ncpus = len(os.sched_getaffinity(0))
 except AttributeError:
     ncpus = os.cpu_count()
-NUM_WORKERS = int(os.environ.get("NUM_WORKERS", min(8, ncpus)))
+NUM_WORKERS = int(os.environ.get("NUM_WORKERS", min(4, ncpus)))
 # Make sure DDP uses correct device if applicable
 LOCAL_RANK = os.environ.get("LOCAL_RANK")
 LOCAL_RANK = int(0 if LOCAL_RANK is None else LOCAL_RANK)
diff --git a/doc/env.md b/doc/env.md
index 3cf42b724a..4ca7101236 100644
--- a/doc/env.md
+++ b/doc/env.md
@@ -72,7 +72,7 @@ Default backend.
 
 :::{envvar} NUM_WORKERS
 
-**Default**: 8 or the number of cores (whichever is smaller)
+**Default**: 4 or the number of cores (whichever is smaller)
 
 {{ pytorch_icon }} Number of subprocesses to use for data loading in the PyTorch backend.
 See [PyTorch documentation](https://pytorch.org/docs/stable/data.html) for details.