amd64/127484: Drift problem with FreeBSD 7.0 and 7.1 PRERELEASE

[Torbjorn Granlund]

>Number:         127484
>Category:       amd64
>Synopsis:       Drift problem with FreeBSD 7.0 and 7.1 PRERELEASE
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-amd64
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Sep 18 21:40:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Torbjorn Granlund
>Release:        7.0, 7.1 PRERELEASE
>Organization:
>Environment:
FreeBSD carlos.gmplib.org 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #0: Tue Sep 16 22:32:59 CEST 2008     root at carlos.gmplib.org:/usr/src/sys/amd64/compile/GENERIC  amd64

>Description:
The clock on this system goes several percent too slowly.

I have tried all available timecounters (the default HPET, as well as
ACPI-safe and i8254.  TSC strangely says (-100) which might suggest
it is not reliable on this system.

The clock drift problem seems to be exactly the same with all
timecounters.

I have also tried setting kern.hz to 100 (in /boot/loader.conf) without
any improvements.

kern.timecounter.choice: TSC(-100) HPET(900) ACPI-safe(850) i8254(0) dummy(-1000000)

Motherboard: ASUS M3A78-EMH HDMI
CPU: AMD Phenom 9750  (2.4 GHz x 4)

I have run FreeBSD for 13 years on countless systems and have never
experienced clock drift problems with it.  Could this be a hardware
problem?
>How-To-Repeat:

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: