WebSTONE Benchmark of IIS May Show Poor Results for MP Systems

• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server version 4.0

SYMPTOMS

Internet Information Server (IIS) performance drops dramatically on multiprocessor systems when you test with WebSTONE, a popular web benchmark, which uses a non-abortive (graceful) close method for TCP sessions.

SPECWEB is another benchmark tool that has shown similar results.

NOTE: This problem does not occur when using regular real-world browsers such as Internet Explorer or Netscape Navigator.

CAUSE

There was a high rate of contention for a TCP resource, which lead to poor performance.

RESOLUTION

Microsoft has updated Tcpip.sys to correct the problem. Instructions for installing it are available from Microsoft support channels, or directly from the following Internet location:

   ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/
   hotfixes-postSP2/TCPIP-fix

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.51 and 4.0. A supported fix is now available, but is not fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.