I have a quad socket octo-core system running FreeBSD. Currently, I need to turn off HyperThreading to get it to boot, as FreeBSD only supports 32 CPUs. There were some patches made awhile ago against a trunk version of 8.1, but even after modifying them slightly to work and compile with 8.1-RELEASE, the machine wouldn't boot.
Has there been any progress here? I can't find much good information about it, Google thinks I'm talking about 64-bit architecture and not literally 64 CPUs.
At the end of http://forums.freebsd.org/showthread.php?t=13261, a FreeBSD developer mentions that
AFAIR it was told somewhere that for 64bit archs it should be possible to rise [the number of logical cores] up to 64 without much troubles, except increased memory consumption. It just wasn't tested due to lack of such systems. Further increase will probably require some architectural changes.
That comment was made in April 2010. Earlier posts in the thread quote an include file which specifies the number of cores.
It might help to remember that Google will let you filter out things using syntax like -"64-bit" — though in this case, and perhaps others, the quoted result would have been filtered out. I got there by googling freebsd max cores.
Note that MAXCPU was recently bumped to 256, but only in 11-CURRENT.
