Re: HOWTO donate CPU to the fight against the Corona-virus

On Sunday, March 22, 2020 11:38:31 AM CEST Stefan Ehmann wrote:
> On Saturday, March 21, 2020 12:07:55 PM CET Alexander Leidinger wrote:
> > Quoting Stefan Ehmann <shoesoft_at_gmx.net> (from Sat, 21 Mar 2020
> >
> > 11:38:26 +0100):
> > > On Thursday, March 19, 2020 8:57:45 AM CET Alexander Leidinger via
> > > freebsd-
> > >
> > > stable wrote:
> > >> Hi,
> > >>
> > >> if someone wants to donate some FreeBSD based CPU resources to the
> > >> fight against the Corona-virus, here is a quick HOWTO in terms of
> > >> installing the Folding_at_Home client on FreeBSD:
> > >>
> > >> https://www.leidinger.net/blog/2020/03/19/fighting-the-coronavirus-with
> > >> -f
> > >> ree bsd-foldinghome/
> > >
> > > Unfortunately, (using a CPU slot for the same work unit) TPF is 2-3
> > > times
> > > slower than on Ubuntu for me. Much of the speed difference seems to
> > > be related
> > > to libOpenCL. If remove libOpenCL on Ubuntu, it's still 20-30% faster
> > > than
> > > on FreeBSD.
> >
> > The pure CPU based code should be the same. Someone would have to
> > trace / reverse engineer what is going on.
>
> I'm pretty sure now that libOpenCL is only relevant for GPU slots.
>
> I couldn't reproduce that the presence of libOpenCL.so has any effect on CPU
> slots. Didn't make much sense anyway, something else must have been going
> on. So there's probably no point in getting OpenCL to run on FreeBSD until
> we have GPU rendering.
>
> The numbers displayed by FAHControl are rather strange:
> * There is no discernible difference in speed if 1 or all CPU cores are used
> (but top shows that 600% CPU cycles are burned) - happens on both Ubuntu
> and Linuxolator
> * According to the progress bar, Ubuntu completes 1% per minute, but
> Linuxolator only 0.1% (for the same work unit)
>
> Don't know if the numbers displayed are bogus or there is really that much
> of a difference. Maybe the issue is only related to a specific WU or to
> AMD-CPUs.

Just a short update:
I've tested the port with a different WU and everything seems normal. Speed is
comparable to Linux and multi-core also works as expected.

My previous problems can probably be ignored, not sure what the problem
actually was.