Slow Copying from WinNT to Win95 in Bus Mastering Mode

Last reviewed: July 30, 1997
Article ID: Q169225

The information in this article applies to:

Microsoft Windows NT Workstation version 4.0
Microsoft Windows NT Server version 4.0
Microsoft Windows 95

SYMPTOMS

When you use IPX protocol in a computer with the network adapter card running in either Bus Mastering Mode or Slave Mode, throughput may be extremely low when attempting to pull (or copy) a file from a computer running Windows NT 4.0 to a computer running Windows 95 or OSR2.

MORE INFORMATION

This problem is not exhibited when attempting to pull a file the other way -- that is, attempting to pull a file from a computer running Windows 95 to a computer running Windows NT 4.0. Also, this problem is NOT exhibited when pulling files from a computer running Windows NT to a computer running Windows NT, or from a computer running Windows 95 to a computer running Window 95 or OSR2. Furthermore, this problem is NOT exhibited in any scenario in Windows NT 3.51.

RESOLUTION

On the Computer Running Windows 95

NOTE: For information about how to edit the registry in Windows 95, view the Changing Keys And Values online Help topic in Registry Editor (Regedit.exe). Note that you should make a backup copy of the registry files (System.dat and User.dat) before you edit the registry.

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall Windows 95. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

You can go into the Registry and enable Direct Hosting to speed up the transfer rate. Go to the following registry key:

   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\Vnetsetup

Add the Binary Value “DirectHost”, value set to 1.

-OR-

On the Computer Running Windows NT

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

You can go into the Registry and enable Bus Mastering to speed up the transfer rate. Go to the following registry key:

   KEY_LOCAL_MACHINE\System\CurrentControlSet\Services\<nic driver>\
   Parameters

Click the Edit menu. Click Add value. Add the following information:

   VALUE NAME:   Busmaster
   DATA TYPE :   Reg_SZ
   VALUE     :   Yes

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Keywords          : ntdriver ntgeneral nthowto ntregistry ntsetup NTSrvWkst
Version           : 4.0
Platform          : WINDOWS
Issue type        : kbhowto

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Last reviewed: July 30, 1997
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