Q278678: Slow Performance Accessing Local Drives with Share Name

Article: Q278678
Product(s): Microsoft Windows NT
Version(s): 2000,4.0
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 06-AUG-2002

-------------------------------------------------------------------------------
The information in this article applies to:

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

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.

Additional query words:

======================================================================
Keywords          : kbnetwork 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbwin2000AdvServ kbwin2000AdvServSearch kbwin2000DataServ kbwin2000DataServSearch kbwin2000Serv kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400search kbWinNTS400 kbwin2000ServSearch kbwin2000Search kbwin2000ProSearch kbwin2000Pro kbNTTermServ400 kbNTTermServSearch kbWinAdvServSearch kbWinDataServSearch
Version           : :2000,4.0
Issue type        : kbbug
Solution Type     : kbpending

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.