TSC-low clock slow on WhiskeyLake i7-8565U (HP Spectre x360 13-ap0043dx)

[Konstantin Belousov]

On Mon, Sep 09, 2019 at 04:07:39PM -0400, Neel Chauhan wrote:
> Hi,
> 
> I recently got a HP Spectre x360 13-ap0043dx as a gift and by default 
> the clock runs slower on FreeBSD than Windows or Linux. Yes, I know the 
> ThinkPad is the best laptop for FreeBSD, but getting an X1 Carbon would 
> increase the price of the gift even more which couldn't be done.
> 
> The kern.timecounter.hardware by default is set to TSC-low and the clock 
> is slow on the Spectre x360. Setting it to ACPI-slow resolves this 
> issue.
> 
> The CPU is a Intel WhiskeyLake Core i7-8565U.
> 
> Is the slow TSC-low an issue with WhiskeyLake in general or specifically 
> HP? Is it something else?
> 
> I am considering writing a patch but before I write one, do other people 
> with WhiskeyLake laptops (or newer) have slow clocks (where one second 
> on the system is actually more in real life), or not.

Start with providing full listing dmesg for verbose boot.

Out of blue, try to set
machdep.disable_tsc_calibration=1
in loader.conf and see if this improves things.