https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91030
--- Comment #33 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> --- Well, I am not opposed to it. What we do not want is to pessimize older smaller machines where it does matter a lot. However if Thomas strategy above is adjusted from 32768 to 65536 then out of the box it will work for your system which is the very first one like this we have encountered (it appears unique from my perspective). We are simply trying to strike the balance across a population for which we have a microscopic sample size shown in this PR. We came up with the 8192 before from also a small sample size. I have another machine here where it makes no difference either way and another where it does really good most of the time at 1024 (believe it or not). Thomas approach is an attempt at the heuristic. Now your idea of a page size angle I need to exlore a bit here and see what this thing is doing. I doubt the HPC users are the majority in number but they are certainly highly important. I know many users around here where I am that use gfortran on there office workstations for preliminary testing and development before they go to the big iron to finalize. With the above said, I think your specific needs at 65536 can be satisfied and we do appreciate the data and testing from you. I do wonder if we need to make "Optimizing I/O" a blatently obvious topic right at the TOP of all our documentation on web page as well as docs.