Tasking Option Affects Server Service Priority

Last reviewed: August 28, 1996
Article ID: Q121594

The information in this article applies to:

Microsoft Windows NT operating system version 3.1
Microsoft Windows NT Advanced Server version 3.1
Microsoft Windows NT Workstation version 3.5
Microsoft Windows NT Server version 3.5

SUMMARY

Process and threads in Windows NT run at a variety of priorities. Higher priority processes get more CPU time. The Windows NT server service priority is tied to the priority of the active foreground process. When tuning the performance of your system, it is important to understand the relationship between the server service priority and the foreground process priority.

By default, the server service priority is the same as the foreground process priority. Changing the Tasking option in the System applet of the Control Panel will affect the server service priority.

In addition, it is possible to change the relationship between the foreground and server priority through a Registry parameter.

MORE INFORMATION

In order to change the priority of all server threads in relation to the base priority of the foreground process, you can configure it through the Windows NT Registry.

NOTE: Higher priority can give better server performance at the cost of local responsiveness. Lower priority balances server needs with the needs of other processes on the system.

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.

Start Registry Editor (REGEDT32.EXE) and go to the following subkey:

      HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
      \LanmanServer\Parameters

From the Edit menu, choose Add Value.

Enter the following values:

     Value Name: ThreadPriority
     Data Type:  REG_DWORD
     Decimal:     <value below>

     Decimal Description
     -------------------
      0      Process running at background priority
      1      Server threads running at same priority as foreground
             (Default)
      2      Server threads running one priority higher than foreground
     15      Server threads running at real-time priority (Not Recommended)

   NOTE: A value of 15 should never be used in production. If the
   server becomes busy, other important system process could become
   resource starved.

Quit Registry Editor and restart Windows NT.

WARNING: With the default Server ThreadPriority set to 1, changing the tasking option to "Foreground and Background Applications Equally Responsive" sets the server service priority to the same level as the foreground and background priorities. This could cause your server service to degrade in performance because it must now share time equally with other background processes.

REFERENCES

"Inside Windows NT," by Helen Custer, Microsoft Press Microsoft Windows NT Resource Kit

Additional reference words: prodnt 3.10 3.50
KBCategory: kbnetwork
KBSubCategory: ntnetserv ntregistry NTSrvWkst

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Last reviewed: August 28, 1996
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