A foundational step to getting good performance is working with buckets close to the Hadoop cluster, where "close" is measured in network terms.

Maximum performance is achieved from working with S3 buckets in the same AWS region as the cluster. For example, if your cluster is in North Virginia ("US East"), you will achieve best performance if your S3 bucket is in the same region.

In addition to improving performance, working with local buckets ensures that no bills are incurred for reading from the bucket.