diff --git a/tests/test_data_source.py b/tests/test_data_source.py
index 07e5b1878..302ee3a1c 100644
--- a/tests/test_data_source.py
+++ b/tests/test_data_source.py
@@ -19,10 +19,10 @@ def per_case_test(self, type_case):
         log.info(f"test case: {t.name}, {ca.name}")
 
         filters = ca.filter_rate
-        ca.dataset.prepare(source=DatasetSource.AliyunOSS, check=False, filters=filters)
+        ca.dataset.prepare(source=DatasetSource.AliyunOSS, filters=filters)
         ali_trains = ca.dataset.train_files
 
-        ca.dataset.prepare(check=False, filters=filters)
+        ca.dataset.prepare(filters=filters)
         s3_trains = ca.dataset.train_files
 
         assert ali_trains == s3_trains
diff --git a/tests/test_dataset.py b/tests/test_dataset.py
index c7678c206..d4ccb283d 100644
--- a/tests/test_dataset.py
+++ b/tests/test_dataset.py
@@ -26,7 +26,7 @@ def test_cohere_error(self):
 
     def test_iter_cohere(self):
         cohere_10m = Dataset.COHERE.manager(10_000_000)
-        cohere_10m.prepare(check=False)
+        cohere_10m.prepare()
 
         import time
         before = time.time()
@@ -40,7 +40,7 @@ def test_iter_cohere(self):
     def test_iter_laion(self):
         laion_100m = Dataset.LAION.manager(100_000_000)
         from vectordb_bench.backend.data_source import DatasetSource
-        laion_100m.prepare(source=DatasetSource.AliyunOSS, check=False)
+        laion_100m.prepare(source=DatasetSource.AliyunOSS)
 
         import time
         before = time.time()
@@ -66,7 +66,6 @@ def test_download_small(self):
             openai_50k.data.dir_name.lower(),
             files=files,
             local_ds_root=openai_50k.data_dir,
-            check_etag=False,
         )
 
         os.remove(file_path)
@@ -74,6 +73,5 @@ def test_download_small(self):
             openai_50k.data.dir_name.lower(),
             files=files,
             local_ds_root=openai_50k.data_dir,
-            check_etag=False,
         )
 
diff --git a/vectordb_bench/backend/data_source.py b/vectordb_bench/backend/data_source.py
index 28e3c3636..9e2f172b4 100644
--- a/vectordb_bench/backend/data_source.py
+++ b/vectordb_bench/backend/data_source.py
@@ -3,7 +3,6 @@
 import typing
 from enum import Enum
 from tqdm import tqdm
-from hashlib import md5
 import os
 from abc import ABC, abstractmethod
 
@@ -32,14 +31,13 @@ class DatasetReader(ABC):
     remote_root: str
 
     @abstractmethod
-    def read(self, dataset: str, files: list[str], local_ds_root: pathlib.Path, check_etag: bool = True):
+    def read(self, dataset: str, files: list[str], local_ds_root: pathlib.Path):
         """read dataset files from remote_root to local_ds_root,
 
         Args:
             dataset(str): for instance "sift_small_500k"
             files(list[str]):  all filenames of the dataset
             local_ds_root(pathlib.Path): whether to write the remote data.
-            check_etag(bool): whether to check the etag
         """
         pass
 
@@ -56,7 +54,7 @@ def __init__(self):
         import oss2
         self.bucket = oss2.Bucket(oss2.AnonymousAuth(), self.remote_root, "benchmark", True)
 
-    def validate_file(self, remote: pathlib.Path, local: pathlib.Path, check_etag: bool) -> bool:
+    def validate_file(self, remote: pathlib.Path, local: pathlib.Path) -> bool:
         info = self.bucket.get_object_meta(remote.as_posix())
 
         # check size equal
@@ -65,13 +63,9 @@ def validate_file(self, remote: pathlib.Path, local: pathlib.Path, check_etag: b
             log.info(f"local file: {local} size[{local_size}] not match with remote size[{remote_size}]")
             return False
 
-        # check etag equal
-        if check_etag:
-            return match_etag(info.etag.strip('"').lower(), local)
-
         return True
 
-    def read(self, dataset: str, files: list[str], local_ds_root: pathlib.Path, check_etag: bool = False):
+    def read(self, dataset: str, files: list[str], local_ds_root: pathlib.Path):
         downloads = []
         if not local_ds_root.exists():
             log.info(f"local dataset root path not exist, creating it: {local_ds_root}")
@@ -83,8 +77,7 @@ def read(self, dataset: str, files: list[str], local_ds_root: pathlib.Path, chec
                 remote_file = pathlib.PurePosixPath("benchmark", dataset, file)
                 local_file = local_ds_root.joinpath(file)
 
-                # Don't check etags for Dataset from Aliyun OSS
-                if (not local_file.exists()) or (not self.validate_file(remote_file, local_file, False)):
+                if (not local_file.exists()) or (not self.validate_file(remote_file, local_file)):
                     log.info(f"local file: {local_file} not match with remote: {remote_file}; add to downloading list")
                     downloads.append((remote_file, local_file))
 
@@ -120,7 +113,7 @@ def ls_all(self, dataset: str):
         return names
 
 
-    def read(self, dataset: str, files: list[str], local_ds_root: pathlib.Path, check_etag: bool = True):
+    def read(self, dataset: str, files: list[str], local_ds_root: pathlib.Path):
         downloads = []
         if not local_ds_root.exists():
             log.info(f"local dataset root path not exist, creating it: {local_ds_root}")
@@ -132,7 +125,7 @@ def read(self, dataset: str, files: list[str], local_ds_root: pathlib.Path, chec
                 remote_file = pathlib.PurePosixPath(self.remote_root, dataset, file)
                 local_file = local_ds_root.joinpath(file)
 
-                if (not local_file.exists()) or (not self.validate_file(remote_file, local_file, check_etag)):
+                if (not local_file.exists()) or (not self.validate_file(remote_file, local_file)):
                     log.info(f"local file: {local_file} not match with remote: {remote_file}; add to downloading list")
                     downloads.append(remote_file)
 
@@ -147,7 +140,7 @@ def read(self, dataset: str, files: list[str], local_ds_root: pathlib.Path, chec
         log.info(f"Succeed to download all files, downloaded file count = {len(downloads)}")
 
 
-    def validate_file(self, remote: pathlib.Path, local: pathlib.Path, check_etag: bool) -> bool:
+    def validate_file(self, remote: pathlib.Path, local: pathlib.Path) -> bool:
         # info() uses ls() inside, maybe we only need to ls once
         info = self.fs.info(remote)
 
@@ -157,48 +150,4 @@ def validate_file(self, remote: pathlib.Path, local: pathlib.Path, check_etag: b
             log.info(f"local file: {local} size[{local_size}] not match with remote size[{remote_size}]")
             return False
 
-        # check etag equal
-        if check_etag:
-            return match_etag(info.get('ETag', "").strip('"'), local)
-
         return True
-
-
-def match_etag(expected_etag: str, local_file) -> bool:
-    """Check if local files' etag match with S3"""
-    def factor_of_1MB(filesize, num_parts):
-        x = filesize / int(num_parts)
-        y = x % 1048576
-        return int(x + 1048576 - y)
-
-    def calc_etag(inputfile, partsize):
-        md5_digests = []
-        with open(inputfile, 'rb') as f:
-            for chunk in iter(lambda: f.read(partsize), b''):
-                md5_digests.append(md5(chunk).digest())
-        return md5(b''.join(md5_digests)).hexdigest() + '-' + str(len(md5_digests))
-
-    def possible_partsizes(filesize, num_parts):
-        return lambda partsize: partsize < filesize and (float(filesize) / float(partsize)) <= num_parts
-
-    filesize = os.path.getsize(local_file)
-    le = ""
-    if '-' not in expected_etag: # no spliting uploading
-        with open(local_file, 'rb') as f:
-            le = md5(f.read()).hexdigest()
-            log.debug(f"calculated local etag {le}, expected etag: {expected_etag}")
-            return expected_etag == le
-    else:
-        num_parts = int(expected_etag.split('-')[-1])
-        partsizes = [ ## Default Partsizes Map
-            8388608, # aws_cli/boto3
-            15728640, # s3cmd
-            factor_of_1MB(filesize, num_parts) # Used by many clients to upload large files
-        ]
-
-        for partsize in filter(possible_partsizes(filesize, num_parts), partsizes):
-            le = calc_etag(local_file, partsize)
-            log.debug(f"calculated local etag {le}, expected etag: {expected_etag}")
-            if expected_etag == le:
-                return True
-    return False
diff --git a/vectordb_bench/backend/dataset.py b/vectordb_bench/backend/dataset.py
index ffe5b10f0..2b630eae3 100644
--- a/vectordb_bench/backend/dataset.py
+++ b/vectordb_bench/backend/dataset.py
@@ -162,7 +162,6 @@ def __iter__(self):
     # TODO passing use_shuffle from outside
     def prepare(self,
         source: DatasetSource=DatasetSource.S3,
-        check: bool=True,
         filters: int | float | str | None = None,
     ) -> bool:
         """Download the dataset from DatasetSource
@@ -170,7 +169,6 @@ def prepare(self,
 
         Args:
             source(DatasetSource): S3 or AliyunOSS, default as S3
-            check(bool): Whether to do etags check, default as ture
             filters(Optional[int | float | str]): combined with dataset's with_gt to
               compose the correct ground_truth file
 
@@ -192,7 +190,6 @@ def prepare(self,
             dataset=self.data.dir_name.lower(),
             files=all_files,
             local_ds_root=self.data_dir,
-            check_etag=check,
         )
 
         if gt_file is not None and test_file is not None: