The last security advisory FreeBSD-SA-06:14.fpu ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-06:14.fpu.asc that fixes very doubtful security bug in AMD CPUs, also adds unnecessary penalty in FPU context switch for all other SSE-enabled CPUs. Igor Sysoev http://sysoev.ru/en/