diff --git a/model_training_nnn_tpu/rnn_args.yaml b/model_training_nnn_tpu/rnn_args.yaml
index 227bc43..4977a59 100644
--- a/model_training_nnn_tpu/rnn_args.yaml
+++ b/model_training_nnn_tpu/rnn_args.yaml
@@ -1,9 +1,9 @@
 model:
   n_input_features: 512 # number of input features in the neural data. (2 features per electrode, 256 electrodes)
-  n_units: 256 # number of units per GRU layer (大幅减少从768→256, 减少70%参数量)
+  n_units: 768 # number of units per GRU layer (大幅减少从768→256, 减少70%参数量)
   rnn_dropout: 0.4 # dropout rate for the GRU layers
   rnn_trainable: true # whether the GRU layers are trainable
-  n_layers: 3 # number of GRU layers (从5层减少到3层)
+  n_layers: 5 # number of GRU layers (从5层减少到3层)
   patch_size: 14 # size of the input patches (14 time steps)
   patch_stride: 4 # stride for the input patches (4 time steps)
 
@@ -74,7 +74,7 @@ dataset:
     smooth_kernel_std: 2 # standard deviation of the smoothing kernel applied to the data
 
   neural_dim: 512 # dimensionality of the neural data
-  batch_size: 1024 # batch size for training (reduced for TPU memory constraints)
+  batch_size: 256 # batch size for training (reduced for TPU memory constraints)
   n_classes: 41 # number of classes (phonemes) in the dataset
   max_seq_elements: 500 # maximum number of sequence elements (phonemes) for any trial
   days_per_batch: 4 # number of randomly-selected days to include in each batch
diff --git a/model_training_nnn_tpu/trainer_tf.py b/model_training_nnn_tpu/trainer_tf.py
index 3628a7d..5438999 100644
--- a/model_training_nnn_tpu/trainer_tf.py
+++ b/model_training_nnn_tpu/trainer_tf.py
@@ -628,9 +628,18 @@ class BrainToTextDecoderTrainerTF:
             self.args['dataset']['data_transforms'],
             training=False
         )
-        # Distribute datasets
+        # Distribute datasets with timing
+        self.logger.info("🔄 Distributing training dataset across TPU cores...")
+        dist_start_time = time.time()
         train_dist_dataset = self.strategy.experimental_distribute_dataset(train_dataset)
+        train_dist_time = time.time() - dist_start_time
+        self.logger.info(f"✅ Training dataset distributed in {train_dist_time:.2f}s")
+
+        self.logger.info("🔄 Distributing validation dataset across TPU cores...")
+        val_start_time = time.time()
         val_dist_dataset = self.strategy.experimental_distribute_dataset(val_dataset)
+        val_dist_time = time.time() - val_start_time
+        self.logger.info(f"✅ Validation dataset distributed in {val_dist_time:.2f}s")
 
         self.logger.info("Created distributed training and validation datasets")
         # Training metrics
@@ -644,7 +653,15 @@ class BrainToTextDecoderTrainerTF:
 
         # Training loop
         step = 0
+
+        # Add timing diagnostic for first batch iteration
+        self.logger.info("🔄 Starting training loop iteration...")
+        loop_start_time = time.time()
+
         for batch in train_dist_dataset:
+            if step == 0:
+                first_batch_iteration_time = time.time() - loop_start_time
+                self.logger.info(f"✅ First batch iteration completed in {first_batch_iteration_time:.2f}s")
             if step >= self.args['num_training_batches']:
                 self.logger.info("Reached maximum training batches, stopping training")
                 break