Re: Status of Alder Lake support

Thanks for the info, Alexander. I really appreciate it. I'll find out for
myself next week when my SSD gets here, though I might try booting from a
thumb drive and see what happens.

On Fri, Aug 19, 2022, 18:43 Alexander Motin <mav@freebsd.org> wrote:

> Hi Kevin,
>
> On 19.08.2022 20:50, Kevin Oberman wrote:
> > What is the current state of support for Alder Lake CPUs with a mix of
> > "performance" and "Efficiency"  cores. I just received my first system
> > with such a processor and will be installing FreeBSD as soon as my SSD
> > arrives. I have no idea what issues I might run into. (Will it even
> work?)
>
> Generally they work.  I have one in my lab since they appeared, and its
> biggest problem is UEFI console screwed by ASUS, which I partially
> fixed.  At some BIOS versions they also broke PXE booting, but then
> fixed it in later update.
>
> The FreeBSD scheduler still has no idea about P and E cores, just trying
> to balance load equally based on cache topology (which is not symmetric
> there), but it is not too bad, since cores performance is not so
> dramatically different.
>
> hwpmc(4) also does not differentiate P and E cores, and since they have
> different counters, it means that only few universal architectural
> counters are usable, which are sufficient for basic profiling though.
>
> There were some stability issues reported, but were solved by either
> FreeBSD or BIOS update, so still not really diagnosed AFAIK.
>
> --
> Alexander Motin
>