Windows Server 2012 and Windows 8 include a new set of performance counters that can greatly help understand the performance of the SMB file protocol. These include new counters on both the server side and the client side. In this blog post, Jose Barreto calls your attention to the new client-side counters that show the traffic going to a specific file share.
See the complete blog post at http://blogs.technet.com/b/josebda/archive/2012/11/19/windows-server-2012-file-server-tip-new-per-share-smb-client-performance-counters-provide-great-insight.aspx.