On Sun, Apr 11, 2010 at 11:12 PM, Maho NAKATA <cha...@mac.com> wrote:
> Hi FreeBSD developers, > [the original article in Japanese can be found at > http://blog.goo.ne.jp/nakatamaho/e/b5f6fbc3cc6e1ac4947463eb1ca4eb0a ] > > *Abstract* > I compared the peak performance of FreeBSD 8.0/amd64 and Ubuntu 9.10 amd64 > using dgemm > (a linear algebra routine, matrix-matrix multiplication). > I obtained only 70% of theoretical peak performance on FreeBSD 8/amd64 and > almost 95% on Ubuntu 9.10 /amd64. I'm really disappointed. > > *Introduction* > I'm a friend of Gotoh Kazushige, the principal developers of GotoBLAS. He > told me that > FreeBSD is not suitable OS for scientific computing or high performance > computing. He says > (in Japanese and my translation): > > > I guess FreeBSD does page coloring, but I don't think FreeBSD considers > very large cache > > size which recent CPU has. Support of a very large cache on Linux is > still not very will > > sophisticated, but on *BSDs, its worst; they uses too fine memory > allocation method, > > so we cannot expect large continuous physical memory allocation. > These statements about FreeBSD's memory management are wrong, or at least outdated. FreeBSD is very likely to allocate physical memory in contiguous chunks to your memory-hungry application even if automatic superpage promotion does not occur. You should refer your friend to my paper at http://www.usenix.org/events/osdi02/tech/full_papers/navarro/navarro_html/and tell him that FreeBSD >= 7.2 implements a variation on what that paper describes. Regards, Alan _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"