Seagate has quietly expanded its family of Exos Mach.2 hard drives featuring two actuators with four new models that offer higher capacity and increased performance. The new Exos 2X18 HDDs can match SATA solid-state drives in terms of sequential read and write speeds while offering capacities of 16TB and 18TB (up from 14TB with previous generation).
The new Seagate Exos 2X18 family includes six models: two 18TB HDDs with a SATA 6 Gbps and SAS 12 Gbps interface as well as two 16TB SKUs with the said interfaces (via StorageReview). SAS drives are always offered with encryption option. As for performance, Seagate says that the Exos 2X18 SATA version boost with a maximum sustained transfer rate of 554 MBps, whereas SAS models are rated for a maximum sustained transfer rate of 545 MBps, which means that these are the world's fastest HDDs. All four drives also feature an average latency of 4.16 ms as well as 304/560 random read/write IOPS (4K QD16).
The dual-actuator drives use conventional magnetic recording, feature a 7,200 RPM spindle speed, a 256MB multisegmented cache, and fully support Seagate's technologies for datacenters, including PowerChoice (to manage idle power consumption), PowerBalance (to manage active power consumption), and hot plug support. Seagate's hermetically sealed and helium-filled Mach.2 hard drives with two actuators are essentially two logical HDDs (of 9TB or 8TB capacity) that are independently addressable and therefore need some software tweaks on the host side.
The key advantage of multi-actuator HDDs in addition to their higher performance compared to single-actuator hard drives is their higher per-TB sequential and random read performance that tends to get lower as hard drive capacity gets higher. Increasing the number of actuators that work independently essentially doubles performance, but this comes at the cost of increased power consumption. The new Exos 2X18 HDDs from Seagate consume 7.8W/8W in idle (SATA/SAS) as well as up to 13.5W/12.8W under heavy loads (SATA/SAS), which is in line with the first-generation Mach.2 HDDs.
Seagate has been experimenting with dual-actuator HDDs with Microsoft since late 2017, but then expanded availability to select other partners. With its Exos 2X18, Seagate probably further expands availability of its Mach.2 HDDs as now it makes them available with a widespread SATA interface. Whether or not such products will be available in retail to those who want an ultra-fast HDD is something that remains to be seen, but at least these SATA drives can be used with a wider range of systems than their predecessors.
Since Seagate's Exos 2X18 drives are designed primarily for datacenters, the company does not disclose their pricing since it heavily depends on volumes and actual configurations.
The new Mach.2 drives come with a five-year warranty and are designed to work in 24/7 environments. Meanwhile, Seagate does not disclose per annum TB workload rating for these HDDs.