diff --git a/mem0/configs/vector_stores/s3_vectors.py b/mem0/configs/vector_stores/s3_vectors.py
index 4118a40861..252e897fdd 100644
--- a/mem0/configs/vector_stores/s3_vectors.py
+++ b/mem0/configs/vector_stores/s3_vectors.py
@@ -16,12 +16,16 @@ class S3VectorsConfig(BaseModel):
     @model_validator(mode="before")
     @classmethod
     def validate_extra_fields(cls, values: Dict[str, Any]) -> Dict[str, Any]:
-        allowed_fields = set(cls.model_fields.keys())
-        input_fields = set(values.keys())
-        extra_fields = input_fields - allowed_fields
+        # Precompute allowed_fields only once per class for efficiency
+        if not hasattr(cls, "_allowed_fields_cache"):
+            # Use tuple instead of set for fixed allowed_fields; should be small and membership is still fast
+            cls._allowed_fields_cache = tuple(cls.model_fields.keys())
+        allowed_fields = cls._allowed_fields_cache
+        # Filter extra fields faster using set difference
+        extra_fields = set(values) - set(allowed_fields)
         if extra_fields:
             raise ValueError(
-                f"Extra fields not allowed: {', '.join(extra_fields)}. Please input only the following fields: {', '.join(allowed_fields)}"
+                f"Extra fields not allowed: {', '.join(sorted(extra_fields))}. Please input only the following fields: {', '.join(sorted(allowed_fields))}"
             )
         return values