Last year, Seagate demonstrated the industry’s first mechanical hard disk (HDD) with a PCIe interface at the Open Computing Project Summit. Like SSDs, it will use the NVMe protocol to work with other SSDs. Although SSDs and HDDs are two different types of storage devices, using the same type of protocol will greatly simplify data center operations.
Recently, Twitter user @harukaze5719 exposed Seagate’s mechanical hard disk using the NVMe protocol, which belongs to its enterprise-level Exos series and is equipped with a U.2 NVMe interface. Compared with the traditional SATA (6Gbps) and SAS (12 Gbps) interfaces, the data transfer rate of the U.2 NVMe interface reaches 32 Gbps, which has a higher upper limit. It is expected that the old SATA and SAS interfaces will be phased out in enterprise data centers, and U.2 backplanes may be used more in future generations of rack-mounted DAS and NAS enclosures, similar to the transition from IDE to SATA for optical drive interfaces in the past.
It is understood that Seagate’s mechanical hard disk using the NVMe protocol should be equipped with a dedicated controller designed by itself, supporting three major protocols, including SAS, SATA, and NVMe. The data transfer rate of existing mechanical hard drives cannot even support a single PCIe 2.0 channel, but products using Mach.2 technology will become faster in the future. So the 12 Gbps provided by SAS and the 6 Gbps interface provided by SATA may not be enough at some point.
At present, major hard disk manufacturers are considering future interface issues, and PCIe seems to be a reasonable choice for a foreseeable period of time. As SSDs are widely used in data centers and the NVMe protocol has become common, Seagate’s HDD is very meaningful, which is why the NVMe 2.0 protocol adds support for HDDs.