Subject: Re: time runs at 1/5th speed
To: Chris Tribo <>
From: Frank Kardel <>
List: current-users
Date: 09/01/2006 15:31:12
Chris Tribo wrote:

> Frank Kardel wrote:
>> Martti Kuparinen wrote:
>>> Hi,
>>> Any ideas why the 4.0_BETA is so slow in time related things inside 
>>> VMware? Maybe GCC 4 related?
>>> ...
> What about this kernel config option and/or switching your timecounter?

switching can be done via sysctl.
sysctl -w kern.timecounter.hardware=i8254
is the usually safest bet (except on SOEKRIS4801).

NetBSD 3 is equivalent with "sysctl -w kern.timecounter.hardware=TSC" with
the exception that no calibration happens to the clock interrupt an thus
this setting is sensitive in environments where cpu speed management affects
the TSC counter. Due to this the timecounter code automatically prefers
i8254 or piixpm0 or ACPI-{Safe/Fast} counters which may or may not be
emulated right in the VMWare environment. I would expect the i8254 counter
to have a correct emulation.

> #options NO_TSC_TIME    # Don't use TSC microtime, even if available.
>             # Improves time behavior under VMware.
That has no effect currently.