Storage controller

A storage controller is a digital circuit that manages the flow of data going to and from a computer storage device.^[1] Its fundamental role is to mediate communication between the host system (like a central processing unit) and the physical storage medium (like magnetic platters or flash cells), translating high-level read/write requests into physical operations and managing the data transfer. The term "storage controller" may refer to several distinct components, depending on the context: the storage interface controller on a CPU or chipset, the flash memory controller on a solid-state drive (SSD), the disk controller on a hard disk drive (HDD), or the management system within an enterprise storage array. Core Functions A storage controller performs several critical tasks essential for the reliable and efficient operation of data storage:

* Protocol Translation and Communication: The controller converts system-level input/output (I/O) requests (e.g., from an operating system) into the specific electronic commands and protocols required by the storage medium (e.g., SATA, SAS, NVMe, Fibre Channel).

History

In history, the storage interface controller is usually integrated in southbridge. AMD Zen 1 archirecture (2017) and Intel Rocket Lake archirecture (2021) had integrated the M.2 storage interface controller in CPU.^[2][3]

Variants

Floppy disk controller

In 1990s PCs, the floppy disk controller is usually integrated in super I/O chip.

IDE controller

In older PCs, the IDE controller is usually integrated in southbridge.^[4]

SCSI controller

In older workstations and servers used as a high-end alternative to consumer-grade IDE hard disk drives. Gave way to Serial Attached SCSI (SAS).

AHCI controller

The AHCI controller is usually integrated in southbridge.^[5]

M.2 controller

The M.2 controller is usually integrated in SoC, CPU, or southbridge.

RAID controller

The RAID controller is usually found on more advanced computers such as servers.

See also

• Memory controller