Evolution of I/O Interfaces Parallel SCSI Serial Attach SCSI
Parallel ATA Serial ATA
Fibre Channel
Single Interface Dual Interfaces
Dual Interfaces Single Interface
Single Interface FC 8Gb/s SAS 6.0 Gb/s
Ultra- 320
Ultra3- SCSI
Ultra2- SCSI
Ultra- SCSI
SCSI Time Here we see the evolution of I/O interfaces over time.
We start with parallel architectures used by ATA and SCSI and see that as the parallel interface reaches its maximum performance potential, it defines the starting point of the new serial architectures.
The exception to this is Fibre Channel which was developed as a serial architecture from the beginning.
Also, the original drive interfaces were single connected options so provided no resilience to failure. This included parallel SCSI, and both parallel and serial ATA interfaces.
Serial Attached SCSI and Fibre Channel both implemented dual interfaces, to be used as a primary and secondary interface for resilience.
ATA SAS 3.0 Gb/s SATA 1.5 Gb/s FC 1Gb/s SATA 3.0 Gb/s FC 2Gb/s SATA 6.0 Gb/s FC 4Gb/s