diff --git a/vall_e/models/ar_nar.py b/vall_e/models/ar_nar.py
index 74e2c8d..50035cf 100644
--- a/vall_e/models/ar_nar.py
+++ b/vall_e/models/ar_nar.py
@@ -17,11 +17,14 @@ import math
 from einops import rearrange
 from torch import Tensor
 from tqdm import trange
+from time import perf_counter
+
 import logging
 
 _logger = logging.getLogger(__name__)
 
 from ..emb.qnt import trim, encode_as_embedding
+from ..utils import get_devices, setup_logging, timer
 
 from .lora import enable_lora
 
@@ -301,7 +304,7 @@ class AR_NAR(Base):
 
 			r = super().sample(
 				logits=logits,
-				prev_list=[ resps_list[i] if task not in text_task else text_list[i] for i, task in enumerate( task_list ) ],
+				prev_list=None if sampling_repetition_penalty == 1.0 and sampling_length_penalty == 0.0 else [ resps_list[i] if task not in text_task else text_list[i] for i, task in enumerate( task_list ) ],
 
 				temperature=sampling_temperature,
 				min_temperature=sampling_min_temperature,
diff --git a/vall_e/models/base.py b/vall_e/models/base.py
index 620b349..6149800 100755
--- a/vall_e/models/base.py
+++ b/vall_e/models/base.py
@@ -1447,7 +1447,7 @@ class Base(nn.Module):
 	def sample(
 		self,
 		logits: list[Tensor], # logit scores
-		prev_list: list[Tensor], # previous tokens
+		prev_list: list[Tensor] | None = None, # previous tokens
 		quant_levels: int | list[int] | Tensor | None = None,
 		# base sampling parameters
 		temperature: float = 1.0,
@@ -1494,11 +1494,12 @@ class Base(nn.Module):
 			return [ logit.argmax(dim=1) for logit in logits ]
 
 		# perform repetition penalizing	
-		if "len" not in self.capabilities:
+		if "len" not in self.capabilities and prev_list is not None:
+			# to-do: figure out a faster way to handle tolist()
 			logits = [ reptition_penalize(logit, previous=prevs[:, -1].tolist() if prevs.dim() > 1 else prevs.tolist(), factor=repetition_penalty, decay=repetition_penalty_decay) for logit, prevs in zip( logits, prev_list ) ]
 
 		# (AR) perform length penalizing
-		if quant_levels is None and self.causal:
+		if quant_levels is None and self.causal and prev_list is not None:
 			logits = [ length_penalize(logit, length=l + 1, factor=length_penalty, token=self.stop_token) for logit, l in zip( logits, map(len, prev_list) ) ]
 
 		# perform top_k/top_p filtering of our logits
diff --git a/vall_e/utils/__init__.py b/vall_e/utils/__init__.py
index 70bc823..c941932 100755
--- a/vall_e/utils/__init__.py
+++ b/vall_e/utils/__init__.py
@@ -10,5 +10,6 @@ from .utils import (
     set_seed,
     passes_policy,
     get_devices,
-    truncate_json
+    truncate_json,
+    timer
 )
\ No newline at end of file
diff --git a/vall_e/utils/utils.py b/vall_e/utils/utils.py
index 8bb98d2..b487c46 100755
--- a/vall_e/utils/utils.py
+++ b/vall_e/utils/utils.py
@@ -25,8 +25,29 @@ from torch import Tensor, nn
 from tqdm.auto import tqdm
 from typing import Callable, TypeVar, overload
 from contextlib import contextmanager
+
+from time import perf_counter
+from datetime import datetime
+
 T = TypeVar("T")
 
+class timer:
+	def __init__(self, msg="Elapsed time:", callback=None):
+		self.msg = msg
+		self.callback = callback
+
+	def __enter__(self):
+		self.start = perf_counter()
+		return self
+
+	def __exit__(self, type, value, traceback):
+		msg = f'{self.msg} {(perf_counter() - self.start):.9f}s'
+
+		if self.callback:
+			self.callback(msg)
+
+		print(f'[{datetime.now().isoformat()}] {msg}')
+
 def truncate_json( str ):
 
 	def fun( match ):
diff --git a/vall_e/webui.py b/vall_e/webui.py
index 5d2d51b..7d5a5e7 100644
--- a/vall_e/webui.py
+++ b/vall_e/webui.py
@@ -9,17 +9,14 @@ import functools
 import torch
 import numpy as np
 
-from datetime import datetime
-
 import torchaudio
 import gradio as gr
 
-from time import perf_counter
 from pathlib import Path
 
 from .inference import TTS, cfg
 from .train import train
-from .utils import get_devices, setup_logging
+from .utils import get_devices, setup_logging, timer
 from .utils.io import json_read, json_stringify
 from .emb.qnt import decode_to_wave
 from .data import get_lang_symmap
@@ -52,20 +49,6 @@ def gradio_wrapper(inputs):
 		return wrapped_function
 	return decorated
 
-class timer:
-	def __init__(self, msg="Elapsed time:"):
-		self.msg = msg
-
-	def __enter__(self):
-		self.start = perf_counter()
-		return self
-
-	def __exit__(self, type, value, traceback):
-		msg = f'{self.msg} {(perf_counter() - self.start):.3f}s'
-
-		gr.Info(msg)
-		print(f'[{datetime.now().isoformat()}] {msg}')
-
 # returns a list of models, assuming the models are placed under ./training/ or ./models/
 def get_model_paths( paths=[Path("./training/"), Path("./models/")] ):
 	yamls = []
@@ -164,7 +147,8 @@ def do_inference_tts( progress=gr.Progress(track_tqdm=True), *args, **kwargs ):
 	parser.add_argument("--references", type=str, default=kwargs["reference"])
 	parser.add_argument("--language", type=str, default=kwargs["language"])
 	parser.add_argument("--input-prompt-length", type=float, default=kwargs["input-prompt-length"])
-	parser.add_argument("--input-prompt-prefix", action='store_true', default=kwargs["input-prompt-prefix"])
+	#parser.add_argument("--input-prompt-prefix", action='store_true', default=kwargs["input-prompt-prefix"])
+	parser.add_argument("--input-prompt-prefix", action='store_true')
 	parser.add_argument("--max-ar-steps", type=int, default=int(kwargs["max-seconds"]*cfg.dataset.frames_per_second))
 	parser.add_argument("--max-nar-levels", type=int, default=0), # kwargs["max-nar-levels"])
 	parser.add_argument("--ar-temp", type=float, default=kwargs["ar-temp"])
@@ -194,7 +178,8 @@ def do_inference_tts( progress=gr.Progress(track_tqdm=True), *args, **kwargs ):
 	tts = init_tts()
 	
 	gr.Info("Inferencing...")
-	with timer("Inferenced in") as t:
+	
+	with timer("Inferenced in", callback=lambda msg: gr.Info( msg )) as t:
 		wav, sr = tts.inference(
 			text=args.text,
 			language=args.language,