SATA 3.5 specification released: bandwidth has not grown, but there is a chance for performance growth

Eleven years ago, the SATA Revision 3.0 specifications were released, which made it possible to double the peak speed of one of the most common interfaces for connecting hard drives. Today, the revision of the SATA specification has reached version 3.5. The maximum exchange rate remained unchanged and froze at 6 Gbit / s. But the developers of the standard promise to increase overall performance and improve integration with other I / O standards.

In general, innovations in SATA Revision 3.5 boil down to three additional features. The first is the technical function of Device Transmit Emphasis for Gen 3 PHY. It allows you to focus on the transmitter, which equates SATA with other I / O solutions when measuring their characteristics. This function should help at the stage of testing and integration of interfaces of new devices.

Secondly, the SATA specifications have a function for determining the ordering of NCQ commands or Defined Ordered NCQ Commands. It allows the host to specify the relationship between the teams in the queue and sets the order in which these commands are processed.

The third new extension in SATA Revision 3.5 is the Command Duration Limit Features. It is designed to reduce delays by allowing the host to define the quality of service categories through more detailed control of the properties of commands. This feature also helps align SATA with the Fast Fail requirements established by the Open Compute Project (OCP) and specified in the INCITS T13 Technical Committee standard. Accordingly, the new SATA revision has incorporated all the latest updates to the T13 standard.

Finally, the SATA Revision 3.5 specifications include corrections and refinements to the SATA 3.4 specifications.

It is expected that the optimization of command processing and error correction carried out in the new version of SATA Revision 3.5 will help reduce the number of cases of “congestion” during intensive data transfer via the SATA interface, which is welcome.