Q241672: File Transfers Between Computers Are Slower Than Expected
Article: Q241672
Product(s): Microsoft Windows NT
Version(s): 4.0
Operating System(s):
Keyword(s): kbWinNT400PreSP7Fix
Last Modified: 08-MAY-2002
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft Windows NT Server version 4.0
- Microsoft Windows NT Workstation version 4.0
-------------------------------------------------------------------------------
SYMPTOMS
========
File transfers between Windows NT 4.0-based computers with similar names are
slower than expected. A network trace shows that the data transfer size is
512-byte increments, rather than the 4,096-byte or larger default size used by
Windows NT.
CAUSE
=====
A problem in the redirector (Rdr.sys) causes the workstation to incorrectly mark
a connection to a remote server as "loopback." This occurs when the remote
server has a NetBIOS name that is a subset of the local NetBIOS computer name.
For example, a connection to a server named Test is incorrectly considered a
loopback connection from workstations named Testx, Test1, Testabc, and so on.
The redirector treats loopback connections differently than it does remote
connections. On connections to remote servers, the redirector makes an initial
read or write request of 512 bytes and then increases the request size if both
computers are capable of handling larger requests. On loopback connections, the
entire transfer is in 512-byte increments. Making these small read and write
requests generates network overhead, and the request takes longer to finish.
RESOLUTION
==========
A supported fix is now available from Microsoft, but it is only intended to
correct the problem described in this article and should be applied only to
systems experiencing this specific problem.
To resolve this problem, contact Microsoft Product Support Services to obtain the
fix. For a complete list of Microsoft Product Support Services phone numbers and
information on support costs, please go to the following address on the World
Wide Web:
http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS
NOTE: In special cases, charges that are normally incurred for support calls may
be canceled, if a Microsoft Support Professional determines that a specific
update will resolve your problem. Normal support costs will apply to additional
support questions and issues that do not qualify for the specific update in
question.
The English-language version of this fix should have the following file
attributes or later:
Date Time Size File name Platform
----------------------------------------------
09/14/99 01:08p 265,008 Rdr.sys Intel
09/14/99 01:07p 512,144 Rdr.sys Alpha
STATUS
======
Microsoft has confirmed this to be a problem in Windows NT 4.0.
Additional query words: slow performance core mode raw
======================================================================
Keywords : kbWinNT400PreSP7Fix
Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400
Version : :4.0
Hardware : ALPHA x86
Issue type : kbbug
Solution Type : kbfix
=============================================================================
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.