diff --git a/trinity/trainer/trainer.py b/trinity/trainer/trainer.py
index dfd4638e38..d9036e9486 100644
--- a/trinity/trainer/trainer.py
+++ b/trinity/trainer/trainer.py
@@ -121,10 +121,8 @@ async def _sample_data(self) -> Tuple[Experiences, Dict, List[Dict]]:
             Dict: Metrics of the sampling step.
             List[Dict]: A list of representative samples for logging.
         """
-        with Timer({}, "time/sample_data"):
-            batch, metrics, repr_samples = await self.sample_strategy.sample(
-                self.train_step_num + 1
-            )
+        batch, metrics, repr_samples = await self.sample_strategy.sample(self.train_step_num + 1)
+        metrics["sample/task_count"] = len(set(eid.task for eid in batch.eids))
         return batch, metrics, repr_samples
 
     async def need_sync(self) -> bool: