diff --git a/cmd/root.go b/cmd/root.go
index b7607f3..02c669c 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -229,10 +229,10 @@ func init() {
 	rootCmd.PersistentFlags().String("migrator-destination-s3-secretAccessKey", "", "S3 secret access key for migrator destination")
 	rootCmd.PersistentFlags().String("migrator-destination-s3-endpoint", "", "S3 endpoint URL for migrator destination")
 	rootCmd.PersistentFlags().String("migrator-destination-s3-format", "parquet", "S3 storage format for migrator destination")
-	rootCmd.PersistentFlags().Int64("migrator-destination-s3-bufferSizeMB", 512, "S3 buffer size in MB before flush for migrator destination")
-	rootCmd.PersistentFlags().Int("migrator-destination-s3-bufferTimeoutSeconds", 300, "S3 buffer timeout in seconds before flush for migrator destination")
+	rootCmd.PersistentFlags().Int64("migrator-destination-s3-bufferSizeMB", 0, "S3 buffer size in MB before flush for migrator destination")
+	rootCmd.PersistentFlags().Int("migrator-destination-s3-bufferTimeoutSeconds", 0, "S3 buffer timeout in seconds before flush for migrator destination")
 	rootCmd.PersistentFlags().Int("migrator-destination-s3-maxBlocksPerFile", 0, "S3 max blocks per file for migrator destination")
-	rootCmd.PersistentFlags().Uint("migrator-batchSize", 2000, "Batch size for storage operations in migrator")
+	rootCmd.PersistentFlags().Uint("migrator-batchSize", 0, "Batch size for storage operations in migrator")
 	rootCmd.PersistentFlags().Uint("migrator-startBlock", 0, "Start block for migration")
 	rootCmd.PersistentFlags().Uint("migrator-endBlock", 0, "End block for migration")
 	rootCmd.PersistentFlags().Uint("migrator-workerCount", 0, "Worker count for migration")
diff --git a/internal/storage/s3.go b/internal/storage/s3.go
index 2e37aa6..a0b51ae 100644
--- a/internal/storage/s3.go
+++ b/internal/storage/s3.go
@@ -97,12 +97,11 @@ func NewS3Connector(cfg *config.S3StorageConfig) (*S3Connector, error) {
 		}
 	}
 
-	// Set buffer defaults
 	if cfg.BufferSize == 0 {
-		cfg.BufferSize = 1024 // 1GB default
+		cfg.BufferSize = 512 // 512MB default
 	}
 	if cfg.BufferTimeout == 0 {
-		cfg.BufferTimeout = 300 // 5 minutes default
+		cfg.BufferTimeout = 1 * 60 * 60 // 1 hour in seconds default
 	}
 
 	// Create formatter based on format