How exactly does a SAS SFF-8087 breakout cable work? + RAID/connection questions

A few items to help clarify SAS technology...

SATA drives can connect to SAS ports.
SAS drives cannot connect to SATA ports.
Server-class hardware typically uses an embedded RAID controller or a separate RAID controller PCIe device.
Most RAID controllers and SAS HBAs will use SAS connections (multilane or 4-lane SAS ports).
Internally, these systems will use one of the internal SAS transports (SFF-8087 or SFF-8484) for cabling.
4-lane SAS cables carry FOUR SAS links over the same cable.
Enterprise servers will typically have a SAS backplane for hot-swap hard drives. These backplanes can accommodate SAS and SATA disks. The backplanes also provide power to the drives. It doesn't make sense to run SATA cables to hot-swappable hard drives. Instead, the internal SAS cables will link the controller and the backplane.
You can mix and match SATA and SAS on the same backplane, but because the protocols are different, bad things. can happen.

Internal SAS 4-lane cabling to a backplane enter image description here

Internal SAS breakout cabling to a backplane enter image description here

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