Slow Performance Accessing Local Drives with Share Name (278678)

The information in this article applies to:

Microsoft Windows NT Server 4.0 Terminal Server Edition
Microsoft Windows 2000 Server
Microsoft Windows 2000 Advanced Server
Microsoft Windows 2000 Professional
Microsoft Windows 2000 Datacenter Server
Microsoft Windows NT Workstation 4.0
Microsoft Windows NT Server 4.0
Microsoft Windows NT Server, Enterprise Edition 4.0

This article was previously published under Q278678

SYMPTOMS

If you share folders on a local computer and then access these local file systems by using their share names, transferring files may be much slower than when you use local drive and path names.

CAUSE

This behavior can occur if TCP/IP is installed as one of the network protocols. When you use share names to access local file systems, the data passes through server, redirector, and network protocol code. The TCP/IP loopback code handles the data inefficiently and causes a bottleneck.

RESOLUTION

If you use NetBEUI as the only protocol, this problem does not occur. Or, if you use \\ipaddr\sharename instead of \\server\sharename, where ipaddr is the local IP address of your network adapter, the loopback code is not used, avoiding the bottleneck.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

Using server, redirector, and networking code adds additional overhead. Microsoft does not recommend accessing local file systems by using share names.

Modification Type:	Major	Last Reviewed:	6/28/2004
Keywords:	kbbug kbnetwork kbpending KB278678