NFS version 4, published in April 2003, introduced stateful client-server interaction and "file delegation" which allows a client to gain temporary exclusive access to a file on a server. NFSv4 brings security improvements such as RPCSEC_GSS, the ability to send multiple operations to the server at once, new file attributes, replication, client side caching, and improved file locking. Although there are a number of improvements in NFSv4 over previous versions, this article investigates just one of them -- performance.