diff --git a/smdebug/core/access_layer/s3.py b/smdebug/core/access_layer/s3.py
index 3e46fc407..4c45b6f8a 100644
--- a/smdebug/core/access_layer/s3.py
+++ b/smdebug/core/access_layer/s3.py
@@ -1,9 +1,12 @@
 # Standard Library
+import io
 import os
 import re
+import tempfile
 
 # Third Party
 import boto3
+from boto3.s3.transfer import TransferConfig
 
 # First Party
 from smdebug.core.access_layer.base import TSAccessBase
@@ -28,6 +31,10 @@ def __init__(
         self.s3 = boto3.resource("s3", region_name=get_region())
         self.s3_client = boto3.client("s3", region_name=get_region())
 
+        # Set the desired multipart threshold value (5GB)
+        MB = 1024 ** 2
+        self.transfer_config = TransferConfig(multipart_threshold=5 * MB)
+
         # check if the bucket exists
         buckets = [bucket["Name"] for bucket in self.s3_client.list_buckets()["Buckets"]]
         if self.bucket_name not in buckets:
@@ -39,17 +46,12 @@ def _init_data(self):
         else:
             self.data = ""
 
-    def _init_data(self):
-        if self.binary:
-            self.data = bytearray()
-        else:
-            self.data = ""
-
     def open(self, bucket_name, mode):
         raise NotImplementedError
 
     def write(self, _data):
         start = len(self.data)
+
         self.data += _data
         length = len(_data)
         return [start, length]
@@ -57,8 +59,25 @@ def write(self, _data):
     def close(self):
         if self.flushed:
             return
-        key = self.s3.Object(self.bucket_name, self.key_name)
-        key.put(Body=self.data)
+        if self.binary:
+            self.logger.debug(
+                f"Sagemaker-Debugger: Writing binary data to s3://{os.path.join(self.bucket_name, self.key_name)}"
+            )
+            self.s3_client.upload_fileobj(
+                io.BytesIO(self.data), self.bucket_name, self.key_name, Config=self.transfer_config
+            )
+        else:
+            f = tempfile.NamedTemporaryFile(mode="w+")
+            self.logger.debug(
+                f"Sagemaker-Debugger: Writing string data to s3://{os.path.join(self.bucket_name, self.key_name)}"
+            )
+
+            f.write(self.data)
+            f.flush()
+            self.s3_client.upload_file(
+                f.name, self.bucket_name, self.key_name, Config=self.transfer_config
+            )
+
         self.logger.debug(
             f"Sagemaker-Debugger: Wrote {len(self.data)} bytes to file "
             f"s3://{os.path.join(self.bucket_name, self.key_name)}"