Yes. FreeBSD divides support into multiple tiers. Tier 1 architectures, such as i386 or amd64; are fully supported. Tiers 2 and 3 are supported on a if-possible basis. A full explanation of the tier system is available in the Committer's Guide.
A complete list of supported architectures can be found on the platforms page.
Symmetric multi-processor (SMP) systems are generally supported by FreeBSD, although in some cases, BIOS or motherboard bugs may generate some problems.
FreeBSD will take advantage of HyperThreading (HTT) support on Intel® CPUs that support this feature. A kernel with the options SMP feature enabled will automatically detect the additional logical processors.
smp(4) has more details.
Microcode is a method of programmatically implementating hardware level instructions. This allows for CPU bugs to be fixed without replacing the on board chip.
Install sysutils/devcpu-data, then add:
microcode_update_enable="YES"
to /etc/rc.conf