The standard specification of SATA

Enhancements in SATA 2.6 Specification
The new technologies added in SATA 2.6 are mainly targeted at small embedded storage or mobile applications. These technologies include the following items:
1. Built-in sub-card cables and connectors that can install SATA optical drives into small devices (such as small form factor devices).
2. Mini SATA connectors that can install 1.8-inch hard drives into small terminals like UMPCs.
3. With the mini connector specifications available, corresponding built-in or external multi-channel cables and connectors have also been designed for these mini connectors.
4. The NCQ priority has been enhanced, allowing data to dynamically allocate priority levels for data transmission in complex loading environments, avoiding congestion.
5. Notebook computers can disable or not use the NCQ function to avoid slowing down the system performance in cases where the driver is incomplete.

SATA 2.6 version enhances for mobile applications
From the above key points of enhancement, it can be seen that SATA 2.6 version mainly focuses on smaller applications, such as small form factor or UMPC's internal and external specifications. However, for such applications, the number of storage devices is severely limited, and the speed of the storage device itself is affected by various factors such as rotational speed (for example, the 1.8-inch hard drive commonly used in UMPCs has a maximum transfer speed of only around 20 MByte/s, which is less than one-third of that of the traditional 3.5-inch hard drive). The introduction of the SATA specification seems not so necessary. UMPC itself cannot have the support capability for disk arrays, and the application method of leveraging the port connector to connect multiple external storage devices is the only way to unleash the power of SATA.
The shortcomings of traditional mechanical hard drives are all exposed on UMPCs. Not only is the power consumption high, the speed is slow, and the growth rate of capacity is not fast. Therefore, the emerging solid-state drive (SSD) may become a helper for the promotion of SATA bandwidth. However, from another perspective, UMPCs may also have an internal Express Card interface. Compared with SATA, Express Card actually has more advantages in terms of specification expansion, speed performance, and connection method. In the next two to three years, the price and capacity of SSDs still cannot be accepted by the general consumers. Traditional micro hard drives still have their survival space. Therefore, the competition between SATA and Express Card in this aspect is still uncertain.

The next stage of SATA 3.0
The most significant improvement of SATA 3.0 is that it increases the maximum bus transmission bandwidth to 6 Gbps. This significantly expands the application space for ports and connectors, and in external applications with demands for large capacity and high-speed transmission, it can fully utilize its advantages. Meanwhile, connection testing with better durability is also underway, but its detailed content is not yet clear. However, based on its extremely large bandwidth, it actually exceeds the scope of general consumer applications and leans more towards specific professional applications. The market has also become much smaller.
Mechanical hard drives will continue to exist for a long time in the future, and the growth of their transmission speed will maintain the current rate. Therefore, hardware manufacturers will inevitably need to develop more different connection methods to effectively consume these huge bandwidths, so that consumers can more directly feel the benefits brought by the increase in numbers, rather than focusing only on the promotion of written specifications and failing to provide users with benefits in related applications.