AMD CPUID Check for the AMD K-7 Chip Now Allows Write-Combining Feature

ID: Q231949

The information in this article applies to:

SYMPTOMS

When you start your computer, Windows NT 4.0 does a CPUID check for an Intel processor. If the processor is a Pentium II or Pentium III, code paths are opened to allow write-combining. The AMD K-7 processor also has the write-combining functionality, but the feature is not enabled when the kernel is initialized.


CAUSE

This problem occurs because the code was not in place to enable the write-combining functionality for the AMD K-7 processor.


RESOLUTION

A supported fix that corrects this problem is now available from Microsoft, but it has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next Windows NT 4.0 service pack that contains this fix.

To resolve this problem immediately, 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://www.microsoft.com/support/supportnet/overview/overview.asp
The English version of this fix should have the following file attributes or later:

   Date      Time      Size        File name      Platform
   --------------------------------------------------------
   05/04/99   03:06p     948,864   Ntkrnlmp.exe   x86
   05/04/99   03:03p     928,768   Ntoskrnl.exe   x86

   05/04/99   03:05p   1,414,272   Ntkrnlmp.exe   Alpha
   05/04/99   03:02p   1,385,728   Ntoskrnl.exe   Alpha

NOTE: If this product was already installed on your computer when you purchased it from the Original Equipment Manufacturer (OEM) and you need this fix, please call the Pay Per Incident number listed on the above Web site. If you contact Microsoft to obtain this fix, and if it is determined that you only require the fix you requested, no fee will be charged. However, if you request additional technical support, and if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support, you may be charged a non-refundable fee.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:
Q154871 Determining If You Are Eligible for No-Charge Technical Support


STATUS

Microsoft has confirmed this to be a problem in Windows NT 4.0.

Additional query words: 


Keywords          : kbbug4.00 kbfix4.00 
Version           : winnt:4.0
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: July 2, 1999