Re: More progress to report [Re: Debian Bullseye on Raspberry Pi 4 4GB?]
On Tue, Mar 2, 2021 at 10:43 PM Jeffrey Walton <noloader@gmail.com> wrote:
>
> On Tue, Mar 2, 2021 at 3:48 PM Arnd Bergmann <arnd@kernel.org> wrote:
> >
> > On Tue, Mar 2, 2021 at 7:51 PM LinAdmin <linadmin@quickline.ch> wrote:
> >
> > > > There is really no good reason to run a 32-bit /kernel/ on the Pi 4,
> > > > especially the version
> > > > with 8GB RAM. While the bug should get fixed in principle to make the
> > > > default kernel
> > > > work and allow installing a 32-bit distro, the best setup for this
> > > > machine (especially
> > > > the versions with less than 4GB) is to use an armhf user space with a
> > > > 64-bit kernel.
> > >
> > > Benchmarking shows that the Pi4 with 32 bit kernel has about
> > > double performance compared to 64 bit kernel!!!
> >
> > Can be more specific about what benchmarks and who ran them?
> > This seems highly unlikely.
>
> Maybe https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=956418?
Cortex-a72 does not have those instructions, and they are only
available on 64-bit code (user and kernel space), so this would make
64-bit kernels run faster on some other SoC, but it won't affect
the performance of 32-bit user space, or anything on Raspberry Pi 4.
Arnd
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