Unpredictable Behavior on Compaq Alpha Computers with EV6

ID: Q219358

The information in this article applies to:

SYMPTOMS

After you install Windows NT 4.0 Service Pack 4 (SP4) on one of the following Compaq Alpha-based computers that uses the EV6 (21264) chip set from Digital Equipment Corporation (DEC), your computer may stop responding (hang) and display the following error message:

STOP 0x0000000A: IRQL_NOT_LESS_OR_EQUAL
Computers known to exhibit this behavior:


CAUSE

The "Alpha Architecture Reference Manual" (AARM) describes strict rules for using interlocked memory instructions (Third Edition, section 4.2.4, page 4-11). The EV6 (21264) processor and all future Alpha processors are more stringent than their predecessors in requiring that these rules be followed. As a result, code that worked in the past, despite non-compliance with these rules, may not work when it is run on computers featuring the EV6 processor. These problematic instruction sequences could result in a loss of performance, computer hangs, application errors, or damaged data.

The version of the Afd.sys file included with Windows NT 4.0 Service Pack 4 contains code that does not comply with the AARM rules for using interlocked memory instructions.


RESOLUTION

To resolve this issue, update the Afd.sys file with a version that is free of interlocked memory instruction problems. You can obtain this file from your local Compaq Technical Support Office. You can also contact Compaq Technical Support for an updated version of the Afd.sys file at (800)-652-6672.

The third-party contact information included in this article is provided to help you find the technical support you need. This contact information is subject to change without notice. Microsoft in no way guarantees the accuracy of this third-party contact information.


STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was first corrected in Windows NT version 4.0 Service Pack 5.


MORE INFORMATION

For information about how to contact Compaq, please query in the Knowledge Base for one or more of the following articles:

Q65416 Hardware and Software Third-Party Vendor Contact List, A-K

Q60781 Hardware and Software Third-Party Vendor Contact List, L-P

Q60782 Hardware and Software Third-Party Vendor Contact List, Q-Z

Additional query words: corruption crash 


Keywords          : kberrmsg kbhw ntstop kbbug4.00 nt4sp5fix 
Version           : winnt:4.0 SP4
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: June 24, 1999