diff --git a/examples/mlperf/dataloader.py b/examples/mlperf/dataloader.py
index 503ea153b9..13fe3b9405 100644
--- a/examples/mlperf/dataloader.py
+++ b/examples/mlperf/dataloader.py
@@ -1,4 +1,6 @@
-import os, random, pickle, queue, struct, math, functools, hashlib, time
+import functools
+import hashlib
+import os, random, pickle, queue, struct, math
 from typing import List
 from pathlib import Path
 from multiprocessing import Queue, Process, shared_memory, connection, Lock, cpu_count
@@ -530,21 +532,21 @@ class BinIdxDataset:
 
     start = self.idx.tell()
     end = start + self.count * dtypes.int32.itemsize
-    self.sizes = self.idx_t[start:end].bitcast(dtypes.int32).numpy()
+    self.sizes = self.idx_t[start:end].bitcast(dtypes.int32)
 
     start = end
     end = start + self.count * dtypes.int64.itemsize
-    self.pointers = self.idx_t[start:end].bitcast(dtypes.int64).numpy()
+    self.pointers = self.idx_t[start:end].bitcast(dtypes.int64)
 
     start = end
     end = start + doc_count * dtypes.int64.itemsize
-    self.doc_idx = self.idx_t[start:end].bitcast(dtypes.int64).numpy()
+    self.doc_idx = self.idx_t[start:end].bitcast(dtypes.int64)
 
     # bin file
     self.bin_t = Tensor(base_path.with_name(f"{base_path.name}.bin"))
 
   def _index(self, idx) -> tuple[int, int]:
-    return self.pointers[idx], self.sizes[idx]
+    return self.pointers[idx].item(), self.sizes[idx].item()
 
   def get(self, idx, offset:int=0, length:int|None=None):
     ptr, size = self._index(idx)
@@ -626,20 +628,14 @@ class GPTDataset:
 
   # https://github.com/NVIDIA/Megatron-LM/blob/94bd476bd840c2fd4c3ebfc7448c2af220f4832b/megatron/core/datasets/gpt_dataset.py#L558
   def _build_doc_idx(self):
-    print(f"building doc_idx for {self.num_epochs=}, {self.indexed_dataset.count=}")
-    st = time.perf_counter()
-    # doc_idx = np.mgrid[:self.num_epochs, :self.indexed_dataset.count][1]
-    doc_idx = np.arange(self.indexed_dataset.count).reshape(1, -1).repeat(self.num_epochs, axis=0).flatten()
+    doc_idx = np.mgrid[:self.num_epochs, :self.indexed_dataset.count][1]
+    doc_idx = doc_idx.reshape(-1)
     doc_idx = doc_idx.astype(np.int32)
-    at = time.perf_counter()
     if self.shuffle: self.rng.shuffle(doc_idx)
-    print(f"doc_idx built in {at - st:.3f}s, shuffled in {time.perf_counter() - at:.3f}s")
     return doc_idx
 
   def _build_sample_idx(self):
-    print(f"building sample_idx for {self.samples=}, {self.seqlen=}, {self.doc_idx.shape[0]=}")
-    sample_idx_max = max(self.doc_idx.shape[0], self.indexed_dataset.sizes.max())
-    sample_idx = np.empty((self.samples + 1, 2), dtype=np.int64 if sample_idx_max > dtypes.int32.max else np.int32)
+    sample_idx = np.empty((self.samples + 1, 2), dtype=np.int32)
 
     sample_idx_idx, doc_idx_idx, doc_offset = 0, 0, 0
     sample_idx[sample_idx_idx, 0], sample_idx[sample_idx_idx, 1] = doc_idx_idx, doc_offset
@@ -649,7 +645,7 @@ class GPTDataset:
       remaining_seqlen = self.seqlen + 1
       while remaining_seqlen > 0:
         doc_idx = int(self.doc_idx[doc_idx_idx])
-        doc_len = int(self.indexed_dataset.sizes[doc_idx]) - doc_offset
+        doc_len = self.indexed_dataset.sizes[doc_idx].item() - doc_offset
         remaining_seqlen -= doc_len
         if remaining_seqlen <= 0:
           doc_offset += remaining_seqlen + doc_len - 1
@@ -658,7 +654,7 @@ class GPTDataset:
           if doc_idx_idx == len(self.doc_idx) - 1:
             assert sample_idx_idx == self.samples
             doc_idx = int(self.doc_idx[doc_idx_idx])
-            doc_offset = int(self.indexed_dataset.sizes[doc_idx]) - 1
+            doc_offset = self.indexed_dataset.sizes[doc_idx].item() - 1
             break
           doc_idx_idx += 1
           doc_offset = 0
@@ -669,12 +665,8 @@ class GPTDataset:
     return sample_idx
 
   def _build_shuffle_idx(self):
-    print(f"building shuffle_idx for {self.samples=}")
-    st = time.perf_counter()
     shuffle_idx = np.arange(self.samples, dtype=np.int32)
-    at = time.perf_counter()
     if self.shuffle: self.rng.shuffle(shuffle_idx)
-    print(f"shuffle_idx built in {at - st:.3f}s, shuffled in {time.perf_counter() - at:.3f}s")
     return shuffle_idx
 
 class BlendedGPTDataset:
@@ -747,8 +739,8 @@ if __name__ == "__main__":
 
   def load_llama3(val):
     bs = 24
-    samples = 5760 if val else 1_200_000 * 1152
-    seqlen = 8192
+    samples = 5760 if val else 1_200_000
+    seqlen = 512
 
     max_, min_ = 0, math.inf
     for tokens in tqdm(batch_load_llama3(bs, samples, seqlen, Path(getenv("BASEDIR", "/raid/datasets/c4/")), seed=5760, val=bool(val)), total=samples//bs):
diff --git a/examples/mlperf/model_train.py b/examples/mlperf/model_train.py
index 8505fb70fa..ae13e091a8 100644
--- a/examples/mlperf/model_train.py
+++ b/examples/mlperf/model_train.py
@@ -1296,7 +1296,7 @@ def train_llama3():
   SEED               = config["SEED"]                   = getenv("SEED", 5760)
   SEQLEN             = config["SEQLEN"]                 = getenv("SEQLEN", 8192)
   TRAIN_ON_VAL       = config["TRAIN_ON_VAL"]           = getenv("TRAIN_ON_VAL", 0)
-  SAMPLES            = config["SAMPLES"]                = getenv("SAMPLES", 5_760 if TRAIN_ON_VAL else 1_200_000 * 1152)
+  SAMPLES            = config["SAMPLES"]                = getenv("SAMPLES", 5_760 if TRAIN_ON_VAL else 1_200_000)
 
   # LR=1e-4 TRAIN_ON_VAL=1 DEFAULT_FLOAT=bfloat16 FUSE_ARANGE=1 JITBEAM=2 OPTIM_DTYPE=bfloat16 LLAMA3_SIZE=1B WARMUP_STEPS=36 DECAY_STEPS=360 SEQLEN=512 PYTHONPATH=. AMD=1 AMD_LLVM=0 MODEL=llama3 python3 examples/mlperf/model_train.py
   # trains to 7