diff --git a/demo/demo_mlx.py b/demo/demo_mlx.py
index 5f34820..e28a56a 100644
--- a/demo/demo_mlx.py
+++ b/demo/demo_mlx.py
@@ -32,7 +32,7 @@
 
 BEAM_WIDTH = 3
 TIME_TOK_WEIGHTING = -5
-FIRST_ONSET_BUFFER_MS = -100  # Controls onset timing for first generated note
+FIRST_ONSET_BUFFER_MS = -100  # Controls onset timing for first generated not
 
 # HARDWARE: Decoded logits are masked for durations < MIN_NOTE_LEN_MS
 # HARDWARE: Sends early off-msg if pitch is on MIN_NOTE_DELTA_MS before on-msg
@@ -40,17 +40,17 @@
 
 # C4DM Disklavier:
 # MIN_NOTE_DELTA_MS = 40
-# MIN_NOTE_LEN_MS = 50
+# MIN_NOTE_LEN_MS = 100
 # HARDWARE_INPUT_LATENCY_MS = 50
-# HARDWARE_OUTPUT_LATENCY_MS = 150
+# HARDWARE_OUTPUT_LATENCY_MS = 120
 
 # Pianoteq
 MIN_NOTE_DELTA_MS = 0
-MIN_NOTE_LEN_MS = 0
+MIN_NOTE_LEN_MS = 30
 HARDWARE_INPUT_LATENCY_MS = 0
 HARDWARE_OUTPUT_LATENCY_MS = 0
 
-MAX_STREAM_DELAY_MS = 25
+MAX_STREAM_DELAY_MS = 50
 
 file_handler = logging.FileHandler("./demo.log", mode="w")
 file_handler.setLevel(logging.DEBUG)
@@ -158,14 +158,15 @@ def _compile_prefill(
 
     compile_start_time_s = time.time()
     logger.info(f"Compiling prefill (chunk_size={chunk_size})")
-    for _ in range(5):
+    for idx in range(8):
+        start = idx * (MAX_SEQ_LEN - chunk_size) // 7
         mx.eval(
             prefill(
                 model,
                 idxs=mx.ones([1, chunk_size], dtype=mx.int32),
                 input_pos=mx.arange(
-                    MAX_SEQ_LEN - (chunk_size + 1),
-                    MAX_SEQ_LEN - 1,
+                    start,
+                    start + chunk_size,
                     dtype=mx.int32,
                 ),
             )
@@ -243,8 +244,8 @@ def compile_model(model: TransformerLM):
     model = _compile_decode_one(model=model, logger=logger)
     for chunk_size in list(
         {
-            PREFILL_CHUNK_SIZE_L,
-            PREFILL_CHUNK_SIZE,
+            # PREFILL_CHUNK_SIZE_L,
+            # PREFILL_CHUNK_SIZE,
             RECALC_DUR_PREFILL_CHUNK_SIZE,
         }
     ):
@@ -269,9 +270,11 @@ def load_model(
     init_start_time_s = time.time()
     model = TransformerLM(model_config)
     model.load_weights(checkpoint_path, strict=False)
-    nn.quantize(model.model, group_size=64, bits=8)
     model.eval()
 
+    if args.quantize:
+        nn.quantize(model.model, group_size=64, bits=8)
+
     logger.info(
         f"Finished initializing model - took {time.time() - init_start_time_s:.4f} seconds"
     )
@@ -1172,7 +1175,7 @@ def continuous_prefill(
                     msgs.append(msg)
                     msg_cnt += 1
 
-        if msg_cnt >= 10 or seen_sentinel:
+        if msg_cnt >= 10:
             midi = convert_msgs_to_midi(msgs=msgs)
             midi_dict = MidiDict(**midi_to_dict(midi))
 
@@ -1484,6 +1487,11 @@ def parse_args():
         help="wait for note-offs before generating",
         action="store_true",
     )
+    argp.add_argument(
+        "--quantize",
+        help="apply model quantize",
+        action="store_true",
+    )
     argp.add_argument(
         "--save_path",
         type=str,