The standard specification of SATA

The Transformation of the SATA Standard
The term "SATA II" that we commonly encounter was originally the name of a committee. The purpose of this committee was to formulate the earliest SATA 1.x standard. Later, this organization was renamed the SATA International Organization (SATA-IO). However, the name "SATA II" was retained. Due to the differences in functions or support levels among the related products launched by different manufacturers, the naming rules for SATA products vary from one manufacturer to another.
Since SATA-IO did not strictly stipulate naming rules and functional requirements, it caused many problems in product positioning during the initial promotion. Generally, manufacturers mostly use specific functions as the naming rule. Commonly seen names such as SATA 300, SATA 3Gb/s, and SATA 3G, some also directly use "SATA II" as the name for their support specifications. However, as their products have become quite complete in hardware specifications, most have abandoned the past speed naming rules. Moreover, at the end of August 2005, at the autumn IDF exhibition, SATA-IO unified and integrated the previously determined SATA II contents by each manufacturer, such as 3Gbps, local command queue (NCQ), port multiplexer (Port Multipliers), and interface selector (port selectors), into the SATA 2.5 standard specification. This significantly reduced the market disorder. In the first quarter of 2007, SATA-IO released version 2.6 of the specification, and the 3.0 version specification is also about to be released in the second half of the year.
The reality that SATA still needs to face
The emergence of SATA 1.0 represents that the computer industry has officially moved from low-frequency parallel transmission to high-frequency sequential transmission. The initial specification was set at 1.5Gbps, significantly having more transmission power than the previous IDE interface. However, although SATA provides such a wide bus, the speed of hard drives has progressed very slowly, and the speed of disk rotation and density improvement is not fast enough, making the improvement of SATA bus speed not significant.

SATA has become a universal storage interface standard.
One example often cited by many people: riding a 50cc small sheep motorcycle on a 200-kilometer-per-hour expressway. This precisely describes the predicament faced by hard drives. According to the SATA 1.0 specification, its maximum transmission speed is approximately 150 Mbyte/s. Even for high-grade SATA hard drives with rotational speeds of over 10,000 rpm, the continuous transmission speed cannot exceed 100 Mbyte/s. To fully utilize the high bus bandwidth of SATA, disk arrays are necessary. Another way to leverage the high bandwidth advantage of the SATA interface is to use external hard drive devices with port sharing. By dividing the bandwidth of a single SATA port among a varying number of hard drives, in terms of a single hard drive, the transmission speed will not have a greater advantage compared to the IDE interface in the past.

The differences between eSATA connectors and SATA connectors
Secondly, although SATA has the standard for hot plugging, the connecting cables are mostly designed for internal hard drives and can only be plugged and unplugged approximately 200 times at most. Beyond this number of plugging and unplugging, the cable connectors will deteriorate and there is a possibility of damaging the hard drive. Even for the eSTAT cables designed for external applications, the number of plugging and unplugging is still only about 2,500 times, which is far behind that of the USB interface. However, this aspect involves the relationship between cable material and cost. Although theoretically it can achieve a higher number of plugging and unplugging, whether the price can be accepted by consumers is also the key. While SATA cables have an advantage in width, their length is limited to within 2 meters, which is also a considerable limitation for some applications. However, this issue can be solved by xSATA.