diff --git a/examples/grpo_frozen_lake/frozen_lake.yaml b/examples/grpo_frozen_lake/frozen_lake.yaml
index 648bab71bc..84c5022374 100644
--- a/examples/grpo_frozen_lake/frozen_lake.yaml
+++ b/examples/grpo_frozen_lake/frozen_lake.yaml
@@ -43,8 +43,8 @@ buffer:
           env_max_steps: 8
           agent_max_steps: 10
           is_slippery: false
+        repeat_times: 4
         rollout_args:
-          n: 4
           top_p: 0.8
           top_k: 20
     default_workflow_type: 'frozen_lake_workflow'
diff --git a/tests/explorer/explorer_test.py b/tests/explorer/explorer_test.py
index 3470ed3456..c061099437 100644
--- a/tests/explorer/explorer_test.py
+++ b/tests/explorer/explorer_test.py
@@ -48,13 +48,16 @@ def setUp(self):
 class TestExplorerCountdownEval(BaseExplorerCase):
     def test_explorer(self):
         self.config.buffer.explorer_input.taskset = get_unittest_dataset_config("countdown")
-        self.config.buffer.explorer_input.eval_tasksets.extend(
+        eval_tasksets = self.config.buffer.explorer_input.eval_tasksets
+        eval_tasksets.extend(
             [
                 get_unittest_dataset_config("countdown", "test"),
                 get_unittest_dataset_config("eval_short"),
                 get_unittest_dataset_config("eval_long"),
             ]
         )
+        eval_tasksets[1].repeat_times = 6
+        eval_tasksets[2].repeat_times = 10
         self.config.name = f"explore-eval-{datetime.now().strftime('%Y%m%d%H%M%S')}"
         self.config.check_and_update()
         explore(self.config)
@@ -65,8 +68,15 @@ def test_explorer(self):
         self.assertTrue(len(eval_metrics) > 0)
         self.assertEqual(parser.metric_max_step(rollout_metrics[0]), 8)
         self.assertEqual(parser.metric_max_step(eval_metrics[0]), 8)
-        self.assertTrue("eval/eval_short/accuracy/max" in eval_metrics)
-        self.assertTrue("eval/eval_long/accuracy/max" in eval_metrics)
+        for eval_taskset, k_list in zip(eval_tasksets, [[1], [2, 4, 6], [2, 4, 8, 10]]):
+            for eval_stats in ["mean", "best", "worst"]:
+                for k in k_list:
+                    for stats in ["mean", "std"]:
+                        metric_name = "score" if eval_taskset.name == "countdown" else "accuracy"
+                        self.assertIn(
+                            f"eval/{eval_taskset.name}/{metric_name}/{eval_stats}@{k}/{stats}",
+                            eval_metrics,
+                        )
 
 
 class TestExplorerGSM8KRULERNoEval(BaseExplorerCase):
diff --git a/tests/trainer/trainer_test.py b/tests/trainer/trainer_test.py
index 9d8cebbd48..a42b85a3e0 100644
--- a/tests/trainer/trainer_test.py
+++ b/tests/trainer/trainer_test.py
@@ -84,12 +84,11 @@ def test_trainer(self):
         self.config.buffer.explorer_input.taskset.task_selector = TaskSelectorConfig(
             selector_type="shuffle", seed=42
         )
-        self.config.buffer.explorer_input.eval_tasksets.append(
-            get_unittest_dataset_config("countdown", "test")
-        )
-        self.config.buffer.explorer_input.eval_tasksets.append(
-            get_unittest_dataset_config("copy_countdown", "test")
-        )
+        eval_tasksets = self.config.buffer.explorer_input.eval_tasksets
+        eval_tasksets.append(get_unittest_dataset_config("countdown", "test"))
+        eval_tasksets.append(get_unittest_dataset_config("copy_countdown", "test"))
+        eval_tasksets[0].repeat_times = 4
+        eval_tasksets[1].repeat_times = 4
         self.config.trainer.save_interval = 4
         self.config.check_and_update()
         _trainer_config = self.config.trainer.trainer_config
@@ -148,14 +147,15 @@ def test_trainer(self):
         bench(self.config)
         parser = TensorBoardParser(os.path.join(self.config.monitor.cache_dir, "tensorboard"))
         for prefix in ["eval", "bench"]:
-            countdown_metrics = parser.metric_list(f"{prefix}/countdown")
-            copy_countdown_metrics = parser.metric_list(f"{prefix}/copy_countdown")
-            self.assertTrue(len(countdown_metrics) > 0)
-            self.assertTrue(len(copy_countdown_metrics) > 0)
-            countdown_metric_steps = parser.metric_steps(countdown_metrics[0])
-            countdown_copy_metric_steps = parser.metric_steps(copy_countdown_metrics[0])
-            self.assertEqual([0, 4, 8], countdown_metric_steps)
-            self.assertEqual([0, 4, 8], countdown_copy_metric_steps)
+            for taskset_name in ["countdown", "copy_countdown"]:
+                metrics = parser.metric_list(f"{prefix}/{taskset_name}")
+                self.assertTrue(len(metrics) > 0)
+                for eval_stats in ["mean", "best", "worst"]:
+                    for k in [2, 4]:
+                        for stats in ["mean", "std"]:
+                            metric_name = f"{prefix}/{taskset_name}/score/{eval_stats}@{k}/{stats}"
+                            metric_steps = parser.metric_steps(metric_name)
+                            self.assertEqual(metric_steps, [0, 4, 8])
 
     def tearDown(self):
         # remove dir only when the test passed
@@ -969,6 +969,7 @@ def test_trainer(self):
         self.config.buffer.explorer_input.eval_tasksets.append(
             get_unittest_dataset_config("gsm8k", "test")
         )
+        self.config.buffer.explorer_input.eval_tasksets[0].repeat_times = 8
         self.config.model.model_path = get_model_path()
         self.config.algorithm.algorithm_type = "grpo"
         self.config.algorithm.advantage_fn = "grpo"
@@ -1019,8 +1020,12 @@ def test_trainer(self):
         for prefix in ["eval", "bench"]:
             gsm8k_metrics = parser.metric_list(f"{prefix}/gsm8k")
             self.assertTrue(len(gsm8k_metrics) > 0)
-            gsm8k_metric_steps = parser.metric_steps(gsm8k_metrics[0])
-            self.assertEqual([0, 2], gsm8k_metric_steps)
+            for eval_stats in ["mean", "best", "worst"]:
+                for k in [2, 4, 8]:
+                    for stats in ["mean", "std"]:
+                        metric_name = f"{prefix}/gsm8k/accuracy/{eval_stats}@{k}/{stats}"
+                        metric_steps = parser.metric_steps(metric_name)
+                        self.assertEqual(metric_steps, [0, 2])
 
     def tearDown(self):
         shutil.rmtree(self.config.checkpoint_job_dir)
diff --git a/trinity/buffer/reader/file_reader.py b/trinity/buffer/reader/file_reader.py
index c61e25e831..8fa3d4c03d 100644
--- a/trinity/buffer/reader/file_reader.py
+++ b/trinity/buffer/reader/file_reader.py
@@ -176,7 +176,7 @@ def __init__(self, config: StorageConfig):
             total_epochs=self.config.total_epochs if not self.config.is_eval else 1,
             offset=self.config.index,
             drop_last=not self.config.is_eval,
-            total_steps=self.config.total_steps,
+            total_steps=self.config.total_steps if not self.config.is_eval else None,
             enable_progress_bar=self.config.enable_progress_bar,
         )
         self.formatter = FORMATTER.get("task")(config)
diff --git a/trinity/common/config.py b/trinity/common/config.py
index 8ea02095f7..158b82a170 100644
--- a/trinity/common/config.py
+++ b/trinity/common/config.py
@@ -84,7 +84,7 @@ class GenerationConfig:
     logprobs: Optional[int] = None  # 0  # vLLM return `logprobs + 1` elements
     max_tokens: Optional[int] = None  # if None, use model.max_response_tokens
     # repeat each task for `n` times
-    # ! DO NOT SET in `buffer.explorer_input.taskset.rollout_args`
+    # ! DO NOT SET, it will be set by `algorithm.repeat_times` or `buffer.explorer_input.eval_tasksets[i].repeat_times`
     n: int = 1
 
 
@@ -249,10 +249,10 @@ class TasksetConfig:
 
     enable_progress_bar: bool = False
 
+    # ! This setting is only valid for `eval_taskset`; for other taskset, it will be overridden by `algorithm.repeat_times`.
+    repeat_times: int = 1
     # ! DO NOT SET, automatically load from checkpoint
     index: int = 0
-    # ! DO NOT SET, automatically set from algorithm.repeat_times
-    repeat_times: int = 1
     # ! DO NOT SET, automatically set based on train/eval
     is_eval: bool = False
     # ! DO NOT SET, automatically set from buffer.batch_size
@@ -927,7 +927,7 @@ def _check_explorer_input(self) -> None:
             dataset.batch_size = self.buffer.batch_size
             if not dataset.name:
                 dataset.name = f"eval_taskset_{idx}"
-            set_if_none(dataset, "repeat_times", 1)
+
             # eval_workflow has higher priority than workflow in eval tasksets, so we set it first
             set_if_none(dataset, "default_workflow_type", explorer_input.default_eval_workflow_type)
             set_if_none(dataset, "default_workflow_type", explorer_input.default_workflow_type)
diff --git a/trinity/explorer/explorer.py b/trinity/explorer/explorer.py
index 30ece621d3..cb421c2fce 100644
--- a/trinity/explorer/explorer.py
+++ b/trinity/explorer/explorer.py
@@ -397,7 +397,9 @@ async def _finish_eval_step(self, step: Optional[int] = None, prefix: str = "eva
             metric[f"{prefix}/{eval_task_name}/finished_task_count"] = len(statuses)
             metric.update(
                 gather_metrics(
-                    [status.metrics[0] for status in statuses], f"{prefix}/{eval_task_name}"
+                    [status.metrics[0] for status in statuses],
+                    f"{prefix}/{eval_task_name}",
+                    output_stats=["mean", "std"],
                 )
             )
         if self.eval_start_time is not None:
diff --git a/trinity/explorer/scheduler.py b/trinity/explorer/scheduler.py
index aa3b6539b9..e06b783e27 100644
--- a/trinity/explorer/scheduler.py
+++ b/trinity/explorer/scheduler.py
@@ -31,16 +31,15 @@ class TaskWrapper:
     results: List[Tuple[Status, List[Experience]]] = field(default_factory=list)
 
 
-def calculate_task_level_metrics(metrics: List[Dict]) -> Dict[str, float]:
+def calculate_task_level_metrics(metrics: List[Dict], is_eval: bool) -> Dict[str, float]:
     """Calculate task level metrics (mean) from multiple runs of the same task.
 
     Args:
         metrics (`List[Dict]`): A list of metric dictionaries from multiple runs of the same task.
+        is_eval (`bool`): Whether this is an evaluation task.
 
     Returns:
         `Dict[str, float]`: A dictionary of aggregated metrics, where each metric is averaged over all runs.
-
-    TODO: support more aggregation methods like max, min.
     """
     if not metrics:
         return {}
@@ -49,7 +48,27 @@ def calculate_task_level_metrics(metrics: List[Dict]) -> Dict[str, float]:
         for key, value in m.items():
             if isinstance(value, (int, float)):
                 aggregated_metrics[key].append(value)
-    return {key: sum(values) / len(values) for key, values in aggregated_metrics.items() if values}
+    if is_eval:
+        result = {}
+        for key, values in aggregated_metrics.items():
+            if "time/task_execution" in key or "time/run_execution" in key:
+                result[key] = sum(values) / len(values)
+                continue
+            k_list = []
+            k = 2
+            while k < len(values):
+                k_list.append(k)
+                k *= 2
+            k_list.append(len(values))
+            for k in k_list:
+                result[f"{key}/mean@{k}"] = sum(values[:k]) / k
+                result[f"{key}/best@{k}"] = max(values[:k])
+                result[f"{key}/worst@{k}"] = min(values[:k])
+        return result
+    else:
+        return {
+            key: sum(values) / len(values) for key, values in aggregated_metrics.items() if values
+        }
 
 
 class RunnerWrapper:
@@ -340,7 +359,8 @@ def task_done_callback(self, async_task: asyncio.Task):
                         all_success = False
                 # calculate task level metrics
                 task_status = Status(
-                    ok=all_success, metrics=[calculate_task_level_metrics(task_metrics)]
+                    ok=all_success,
+                    metrics=[calculate_task_level_metrics(task_metrics, task.task.is_eval)],
                 )
                 self.completed_tasks[task.batch_id].appendleft((task_status, task_experiences))
                 self.logger.debug(f"Task completed (batch_id {task.batch_id}).")
diff --git a/trinity/explorer/workflow_runner.py b/trinity/explorer/workflow_runner.py
index 314f8b94e0..8917274dd5 100644
--- a/trinity/explorer/workflow_runner.py
+++ b/trinity/explorer/workflow_runner.py
@@ -141,7 +141,7 @@ async def _run_task(
             # repeatable workflow cannot calculate run level metrics, we use experience level metrics directly
             run_metrics = [exp.metrics for exp in exps if exp.metrics]
             for metric in run_metrics:
-                metric["time/task_execution"] = et - st
+                metric["time/run_execution"] = et - st
         else:
             exps = []
             run_metrics = []
@@ -155,7 +155,7 @@ async def _run_task(
                 et = time.time()
                 self.runner_state["terminate_time"] = et
                 run_metric = calculate_run_level_metrics(new_exps)
-                run_metric["time/task_execution"] = et - st
+                run_metric["time/run_execution"] = et - st
                 run_metrics.append(run_metric)
                 for exp in new_exps:
                     exp.eid.run = run_id_base + i
@@ -209,7 +209,7 @@ async def run_task(
             error_trace_back = traceback.format_exc()
             self.logger.error(f"WorkflowRunner run task error: {e}\nTraceback:\n{error_trace_back}")
             return (
-                Status(False, metrics=[{"time/task_execution": time.time() - st}], message=str(e)),
+                Status(False, metrics=[{"time/run_execution": time.time() - st}], message=str(e)),
                 [],
             )
 
diff --git a/trinity/utils/monitor.py b/trinity/utils/monitor.py
index 0eee105608..8ea9446061 100644
--- a/trinity/utils/monitor.py
+++ b/trinity/utils/monitor.py
@@ -25,18 +25,19 @@
 MONITOR = Registry("monitor")
 
 
-def gather_metrics(metric_list: List[Dict], prefix: str) -> Dict:
+def gather_metrics(
+    metric_list: List[Dict], prefix: str, output_stats: List[str] = ["mean", "max", "min"]
+) -> Dict:
     if not metric_list:
         return {}
     try:
         df = pd.DataFrame(metric_list)
         numeric_df = df.select_dtypes(include=[np.number])
-        stats_df = numeric_df.agg(["mean", "max", "min"])
+        stats_df = numeric_df.agg(output_stats)
         metric = {}
         for col in stats_df.columns:
-            metric[f"{prefix}/{col}/mean"] = stats_df.loc["mean", col].item()
-            metric[f"{prefix}/{col}/max"] = stats_df.loc["max", col].item()
-            metric[f"{prefix}/{col}/min"] = stats_df.loc["min", col].item()
+            for stats in output_stats:
+                metric[f"{prefix}/{col}/{stats}"] = stats_df.loc[stats, col].item()
         return metric
     except Exception as e:
         raise ValueError(f"Failed to gather metrics: {e}") from e