diff --git a/scripts/bench_episode_byte_cache.py b/scripts/bench_episode_byte_cache.py
index d07ec7722..453f38139 100644
--- a/scripts/bench_episode_byte_cache.py
+++ b/scripts/bench_episode_byte_cache.py
@@ -165,25 +165,12 @@ def _bytes_for(manifest: EpisodeVideoManifest, episodes: Sequence[int]) -> int:
     return total
 
 
-def _episode_timestamp_window(manifest: EpisodeVideoManifest, episode_index: int) -> tuple[float, float]:
-    spans = [manifest.lookup(episode_index, camera_key) for camera_key in manifest.video_keys]
-    lo = max(span.first_pts for span in spans)
-    hi = min(span.last_pts for span in spans)
-    if hi >= lo:
-        return lo, hi
-    first = spans[0]
-    return first.first_pts, max(first.last_pts, first.first_pts)
-
-
-def _random_training_samples(
-    manifest: EpisodeVideoManifest, episodes: Sequence[int], count: int, seed: int
-) -> list[tuple[int, float]]:
+def _random_training_samples(episodes: Sequence[int], count: int, seed: int) -> list[tuple[int, float]]:
     rng = random.Random(seed)
     out = []
     for _ in range(count):
         ep = rng.choice(episodes)
-        lo, hi = _episode_timestamp_window(manifest, ep)
-        out.append((ep, rng.uniform(lo, max(hi, lo))))
+        out.append((ep, rng.random()))
     return out
 
 
@@ -258,10 +245,12 @@ def _open_resident_decoders(
 def _decode_training_sample(
     cache: EpisodeByteCache,
     episode_index: int,
-    timestamp: float,
+    relative_t: float,
     locks: dict[tuple[int, str], threading.Lock],
 ) -> None:
     for camera_key in cache.manifest.video_keys:
+        span = cache.manifest.lookup(episode_index, camera_key)
+        timestamp = span.first_pts + relative_t * max(span.last_pts - span.first_pts, 0.0)
         with locks[(episode_index, camera_key)]:
             cache.get_frames(episode_index, camera_key, [timestamp])
 
@@ -275,7 +264,7 @@ def run_pool_random_decode(
     decode_workers: int,
     seed: int,
 ) -> dict[str, float]:
-    samples = _random_training_samples(cache.manifest, episodes, sample_count, seed)
+    samples = _random_training_samples(episodes, sample_count, seed)
     touched_episodes = sorted({ep for ep, _ts in samples})
     decoder_open_s, decoder_count = _open_resident_decoders(
         cache, touched_episodes, decode_workers=decode_workers
@@ -371,10 +360,9 @@ def run_pool_stream_simulation(
             schedule_one()
 
         ep = rng.choice(resident)
-        lo, hi = _episode_timestamp_window(cache.manifest, ep)
-        ts = rng.uniform(lo, max(hi, lo))
-        _decode_training_sample(cache, ep, ts, locks)
-        decoded_samples.append((ep, ts))
+        relative_t = rng.random()
+        _decode_training_sample(cache, ep, relative_t, locks)
+        decoded_samples.append((ep, relative_t))
 
         if sample_period > 0:
             now = time.perf_counter()