Amazon requires multipart uploads for large files (>5GB)
"The largest object that can be uploaded in a single PUT is 5 gigabytes. "
https://aws.amazon.com/s3/faqs/

The s3 plug-in uses
http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3Client.html#putObject(com.amazonaws.services.s3.model.PutObjectRequest)

However multipartUpload has to be handled differently http://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3Client.html#initiateMultipartUpload(com.amazonaws.services.s3.model.InitiateMultipartUploadRequest