A Windows Server 2003-based server may experience time-stamp counter drift if the server uses dual-core AMD Opteron processors or multiprocessor AMD Opteron processors

A Windows Server 2003-based server may experience time-stamp counter drift if the server uses dual-core AMD Opteron processors or multiprocessor AMD Opteron processors. When this problem occurs, operations that rely on the time-stamp counter may not function correctly. These operations include network communications and performance monitoring.

If the server is an Active Directory domain controller, you may receive the following error message:When you use the ping command to send Internet Control Message Protocol (ICMP) packets to a remote computer, the reply may show negative response times. For example, the following ping command may generate the following replies:

C:\>ping x.x.x.x

Pinging x.x.x.x with 32 bytes of data:

Reply from x.x.x.x: bytes=32 time=-59ms TTL=128
Reply from x.x.x.x: bytes=32 time=-59ms TTL=128
Reply from x.x.x.x: bytes=32 time=-59ms TTL=128
Reply from x.x.x.x: bytes=32 time=-59ms TTL=128

This problem occurs when the time-stamp counters for different processor cores are not synchronized. Windows Server 2003 uses the time-stamp counter as a timekeeping source. Each processor contains a time-stamp counter.

To resolve this problem, configure Windows Server 2003 to use the PM_TIMER setting instead of the time-stamp counter. To do this, add the /usepmtimer parameter to the Boot.ini file, and then restart the server.

Note The /usepmtimer parameter is automatically added to the Boot.ini file when you install the latest AMD PowerNow! Technology driver from AMD. The updated driver itself does not resolve this problem. However, the installation process makes the necessary changes to the Boot.ini file to resolve this problem.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Only Windows Server 2003 with Service Pack 2 uniprocessor ACPI HALs use PMTIMER for QPC by default. Multiprocessor ACPI HALs will use PMTIMER only if USE_PLATFORM_CLOCK flag is set by the BIOS or if the /usepmtimer boot.ini option is used. Other HAL types don’t support PMTIMER and will use TSC by default for QPC

By default, Windows Server 2003 Service Pack 2 (SP2) uses the PM timer for all Advanced Configuration and Power Interface (ACPI) HALs unless one of the following conditions aretrue:

• The check process to determine whether the BIOS supports the APIC or ACPI HALs fails.
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  Note: If the BIOS does not support the ACPI HAL, contact the original equipment manufacturer to determine whether a BIOS update is available that will resolve the problem. If a BIOS update is not available, you must use the PM timer by using the /usepmtimer switch.

If you are not running Windows Server 2003 SP2, you must force the AMD computer to use the PM timer by using the /usepmtimer switch.

Note The decision to use the PM timer or the TSC timer is made during a check that is performed at startup to query the BIOS and to determine whether the BIOS will support the PM timer functions. This check is not completely accurate on AMD chipsets. Therefore, you must use the /usepmtimer switch.

In Windows Server 2003 SP2, this section of code was rewritten. Therefore, the correct performance monitor data appears on AMD chipsets that have Windows Server 2003 SP2 installed, and you do not have to use the /usepmtimer switch.

For more information about ACPI and APCI hardware support, click the following article number to view the article in the Microsoft Knowledge Base: The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.