This is on an existing FreeBSD install. I'm not booting from the SSD; I'm just adding it so it will show up at /var/cache.
# mkdir /var/cache
I installed the solid-state drive on a Dell OptiPlex 755. I unplugged the SATA cable from the DVD-ROM drive (who uses optical media anymore?) and connected the cable from SATA1 on the motherboard to the SSD.