I am in the process of renaming ~2800 files, and it has been running all night.  Here is the code:

namespace UpdateMetadata
{
    class Program
    {
        static Workspace _ws;

        static void Main(string[] args)
        {
            TeamFoundationServer tfs = TeamFoundationServerFactory.GetServer("http://devtfserver:8080");
            Console.WriteLine("User: {0}", tfs.AuthenticatedUserName );

            VersionControlServer vcs = (VersionControlServer)tfs.GetService(typeof (VersionControlServer));
            _ws = vcs.GetWorkspace(@"<my local workspace folder>");
            DirectoryInfo di = new DirectoryInfo(@"<a subtree (containing the XML files to rename) of my local workspace>");
            ProcessDirectory(di);
        }

        static void ProcessDirectory(DirectoryInfo di)
        {
            FileInfo[] files = di.GetFiles();
            foreach (FileInfo file in files)
            {
                if (Path.GetExtension(file.Name).ToLower() != ".xml")
                {
                    string newName = file.FullName + ".xml";
                    Logger.Info("PendRename {0} => {1}", file.Name, Path.GetFileName(newName));
                    _ws.PendRename(file.FullName, newName);
                }
            }

            DirectoryInfo[] dirs = di.GetDirectories();
            foreach (DirectoryInfo dir in dirs)
            {
                ProcessDirectory(dir);
            }
        }
    }
}

It started off reasonably quickly - even over the VPN; however, it was still running 7 hours later when I awoke.  I started it
again at the office, with a direct connection to the server, however it is taking roughly 35-40 seconds to rename a file.  CPU
usage on my local machine is <1%, context switching is minimal.

It is evident that the server performance has significantly degraded over the duration of this operation, and therefore is the
cause of the performance issues - why?

Cheers,

Stuart