Tim,
> On 3/04/2020, at 2:01 AM, BATES Timothy <tim.ba...@ed.ac.uk> wrote: > > Moving to a compiler that drops support for OpenMP seems a sad choice, > especially now we’ve all climbed the learning curve of the non-Apple compiler > (the real barrier was lack of a pkg installer and that’s done now). > It has caused a lot of issues, it trips people on a daily basis which is just not worth it. Also with Apple's increasingly strict rules about what can be distributed we don't want to be in the business in maintaining a separate toolchain. There have been numerous issues with C++ exceptions so the fall out was much bigger than originally expected and it would only get worse. > Losing OpenMP for the CRAN version of OpenMx/umx (our SEM packages) would be > a big loss for users (for whom the CRAN version now supports OpenMP giving > them a 2-12x speed up). In general, R on Mac is made more viable by having > OpenMP > > Re Brian’s points, I’d say that the distribution problem is crucial: Packages > not on CRAN have dramatically diminished accessibility/useage. > The idea is that if a package deems this critical, it can enable this for the users. As it is now, packages can still supply iomp and use it. That said, I would open for discussion the ability to distribute iomp with the R binary, but it would not be supported by R directly, i.e., it would be on the package author to make sure that the way the package operates is compatible with that binary. Let me know what you think. > Second, a great range of compute-intensive problems are amenable to division > amongst cores, including nearly all models that take more than a nominal > amount of time to run: So simulations, CIs, bootstrapping, nearly everything > in genetics all speeds up. > Yes, but OpenMP is rarely used for those tasks. In R OpenMP can be only used for very small subset of such tasks - which is why alternative approaches are much more common. Cheers, Simon > I’d say especially on desktop/laptop. The big advantage of multi blade > systems requires snowfall-type solutions, but desktops profit automatically > from their multi-core structure and don;’t have multiple processors (except > graphics, which no-one seems to be exploiting on CRAN-style R), so OpenMP is > their one trick. I’d hope not to lose it. > > Best, t > > >> On 2 Apr 2020, at 05:18, Prof Brian Ripley <rip...@stats.ox.ac.uk> wrote: >> >> On 01/04/2020 22:02, Simon Urbanek wrote: >>> JJB, >>> 1. correct, there was too much trouble in this. But please feel free to >>> start a new thread about this here if you have strong opinions. >> >> Also note that it is possible (and not hard) to install packages from source >> with an OpenMP-supporting compiler, and how to do so is in the R-admin >> manual. The problems come in distributing them. >> >> The benefits of OpenMP are often overestimated, especially on desktop/laptop >> level hardware. But it is available for the small (tiny?) proportion of >> users who need it. > The University of Edinburgh is a charitable body, registered in Scotland, > with registration number SC005336. > _______________________________________________ > R-SIG-Mac mailing list > R-SIG-Mac@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-mac _______________________________________________ R-SIG-Mac mailing list R-SIG-Mac@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-mac
