because master/slave doesn’t apply for sata drives
http://www.tomshardware.com/forum/243833-32-primary-secondary-master-slave-sata
My BIOS (hit DEL when booting) example: 2 x SSD HDD’s …
SATA 2 = Windows 7 OS Boot (or Master in old lingo)
SATA 4 = Secondary (or Slave in old lingo)
Swap the SATA Port connection around to reverse