SATA is the abbreviation of Serial ATA, that is, Serial ATA. This is a new type of hard disk interface that is completely different from parallel ATA, and is named after the serial transmission of data.Serial ATA wiring is much simpler than traditional Parallel ATA (Paralle ATA) wiring, and it is easy to retract, which significantly improves airflow and heat dissipation in the chassis. Moreover, SATA hard disks are different from parallel ATAs that are always trapped in the chassis. They are highly expandable and can be externally installed. The external cabinet (JBOD) not only provides better cooling and plugging functions, but also supports multiple Connection to prevent single point of failure; because the design of SATA and Fibre Channel is the same, so the transfer speed can be guaranteed by different channels, which is of great significance in servers and network storage.
SATA II is developed on the basis of SATA. Its main feature is that the external transfer rate is further increased from 1.5Gbps (150MB/sec) of SATA to 3Gbps (300MB/sec), and it also includes NCQ (NaTIve Command Queuing, native Command queue), port multiplexer (Port MulTIplier), staggered start (Staggered Spin-up) and a series of technical features. A purely external transfer rate of 3Gbps is not really SATA II.