|The confusion comes from the references in the BIOS. |
While SATA drives do not share bandwidth they DO share controllers. There are usually two SATA ports per SATA controller. So, a SATA drive can be connected as a slave but still runs independently. That is, unless it is configured as part of a RAID setup.
You may need to enable the SATA controllers in the BIOS screens. Note that SATA drives also require both power and data cables in order to operate.
Watch the POST screens at start up where all the hardware is configured. All your drives should appear by both model number and full drive capacity. If that doesn't happen then they will never work in Windows.