What's going on is:

I think the best place to check for supported (=hardware+software)
processor features is on the client--side.

Everybody else thinks I'm being stupid for thinking that this could be a
problem later on. And even if it turns out to be a problem they think the
best place to check for the support is on the server-side and every project
can code their own checks.

-Juha


On 24 July 2013 00:53, Wolfgang Schwieger <[email protected]> wrote:

> Maybe I am to stupid to understand what's going on, but.....
>
> BOINC reports a cpu feature (AVX) which the cpu has/or has not. (that is
> what we need!)
> BOINC !_also_! reports the OS, the OS version/kernel version, !_and_! the
> installed service pack (for windows).
>
> So, if a project has an application with AVX code, the project (!!!) has to
> decide if/or if not this application will run under an "older" OS.
>
> BOINC just reports the feature, the project admin configures what has to be
> configured.
>
> Wolfgang
>
> -----Ursprüngliche Nachricht-----
> Von: Juha [mailto:[email protected]]
> Gesendet: Dienstag, 23. Juli 2013 22:58
> An: BOINC Developers Mailing List
> Betreff: Re: [boinc_dev] [SPAM] Re: : BOINC (windows) doesn't report avx
> processor feature
>
> On 23 July 2013 04:41, Michael Goetz <[email protected]> wrote:
>
> > I'm not very worried about lock of OS support for AVX, at least as far
> > as PrimeGrid is concerned.
> >
> > * It's unlikely anyone has bought a pre-configured computer with an
> > AVX capable CPU that came with a version of Windows that doesn't support
> AVX.
> >
> > * People who built their own systems and loaded XP?!?! on it are
> > certainly able to load and run Linux if they wish to, and if they
> > loaded Win 7 without SP1 they can load SP1.
> >
> > * It's unclear to me why anyone would buy, sell, or build a computer
> > with an AVX CPU with an operating system that doesn't support the
> > instruction set.  It's possible, but unlikely.
> >
>
> Well, someone could have upgraded to a newer CPU, or replaced a broken
> component without upgrading the OS at the same time. Or they might be stuck
> with an older OS because they have some device for which there's drivers
> only for, say, XP. Or they are forced for some other reasons to keep using
> an older OS. There are reasons once you start looking for them.
>
> And even if none of those hold, people still have the right to be silly and
> keep using XP.
>
>
> > * There's about a 40% increase in speed with the AVX version of that
> > application, so if there's anyone participating in that subproject
> > with such a computer, they probably will want to upgrade or switch
> > their OS to take advantage of the increased performance.
> >
>
> That's a very nice speed-up. But you are assuming that:
> 1. People are paying attention (to such details). Maybe at PrimeGrid that's
> true but I doubt that's true generally speaking. At least at Seti@homethere
> are people turning in thousands and thousands of invalids so obviously they
> don't pay any attention to what their computer does.
> 2. People are buying or configuring their systems to crunch numbers. True
> for some people but I think the majority buys computers for some other
> reason and install BOINC to have something for the computer to do while
> they
> read their emails.
>
>
> > * After all that, if there's actually someone who wants to run their
> > fancy new CPU with an OS that cripples its capabilities, I can always
> > change the plan class to restrict the OS to versions that do support AVX.
> >
>
> There's one problem with that approach. Every project that releases AVX
> application would need to add those restrictions. Wasn't BOINC supposed to
> handle everything that's common to all projects so that projects can then
> concentrate on doing whatever science they do? So IMHO reliable information
> of host's capabilities is something that BOINC should provide, one way or
> the other.
>
> So either the client should report only those processor features that the
> OS
> supports or the scheduler should have a function does_host_support_avx()
> that checks both the reported features and the OS version.
>
> (Generally speaking. There's one benefit for the server side check. If the
> host has support for feature X in hardware but not in software, the server
> could tell the user "Your host has support for feature X and we have an
> application that can take advantage of it. But you need to install Y
> first."
> Similar to what the server currently does with at least NVIDIA
> drivers.)
>
> In short, while this is a theoretical problem, I don't think the lack of
> > AVX support in old versions of Windows is a significant real world
> problem.
> >
>
> That may very well be true, but I still see it as something that could be
> done better, if not even as a bug.
>
> -Juha
>
>
>
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