AWS s3 cli sync multipart upload

Question

AWS s3 cli sync can use multipart upload option?

on-premise server sync to s3 using AWS cli sync

but, speed is very slow.

Answer 1

Assuming you mean the aws command (and not e.g. s3cmd): Yes, sync uses multipart upload by default. From the docs:

All high-level commands that involve uploading objects into an Amazon S3 bucket (aws s3 cp, aws s3 mv, and aws s3 sync) automatically perform a multipart upload when the object is large

I guess the slowness is caused by another factor, e.g. your bandwidth is low (check e.g. with speedtest or it is already saturated