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 _______________________________________________ boinc_dev mailing list [email protected] http://lists.ssl.berkeley.edu/mailman/listinfo/boinc_dev To unsubscribe, visit the above URL and (near bottom of page) enter your email address.
