title: How to migrate millions of files in aws s3 bucket from one account to another really fast
body: <p>I have an s3 bucket in account A with millions of files that take up many GBs</p>
  
  <p>I want to migrate all this data into a new bucket in account B</p>
  
  <p>So far, I've given account B permissions to run s3 commands on the bucket in account A.</p>
  
  <p>I am able to get some results with the 
  <code>aws s3 sync</code> command with the setting <code>aws configure set default.s3.max_concurrent_requests 100</code></p>
  
  <p>its fast but it only does a speed of some 20,000 parts per minute. </p>
  
  <p>Is there an approach to sync/move data across aws buckets in different accounts REALLY fast?</p>
  
  <p>I tried to do aws transfer acceleration but it seems that that is good for uploading and downloading from the buckets and I think it works within an aws account.</p>