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Seagate Releases Spate Of 8 TB Enterprise HDDs

By - Source: Seagate

Seagate recently shipped its 2.4 billionth HDD, and now it is adding a three-pronged spate of 8 TB offerings to its arsenal. Seagate utilizes ninth-generation PMR (Perpendicular Magnetic Recording) for two of its new HDDs, the Enterprise Capacity and Enterprise NAS, and SMR (Shingled Magnetic Recording) for its Kinetic HDD. Seagate is already shipping an 8 TB model with SMR (see our Seagate 8 TB Archive HDD Review), but its limited performance relegates it to backup/archival tasks. The new lineup expands Seagate's 8 TB HDD portfolio to cover every facet of the data center/enterprise/SMB markets.

Seagate's rival HGST is currently the only other manufacturer offering hefty 8 TB HDDs, but it only offers one model. However, HGST utilizes its helium architecture in the Ultrastar He8, which reduces turbulence and flutter by filling the drive with helium instead of air. Helium offers lower power consumption and less heat generation, but when paired with HGST's media cache, it also offers strong performance.

Frankly, HGST enjoys a lead in both performance and power consumption utilizing these two techniques, but Seagate is addressing the performance issue head on.

Enterprise Capacity
Enterprise NAS
Kinetic HDD
8 TB
8, 6, 5 ,4, 3, 2 TB
4, 8 TB
12 Gbps SAS - 6 Gbps SATA
SATA 6 Gbps
 Drive-Managed SMR
Spindle Speed
7,200 RPM
7,200 RPM5,900 RPM
Avg. Latency
4.16 ms
4.16 ms
Sustained Transfer Rate (OD)
up to 230 MB/s
Power (typ.)
10 W
9.0 W
8.25 W
Idle Power
9 W
256 MB DRAM - 2 MB NOR
up to 256 MB
up to 128 MB
Workload (Per Year)
550 TB
300 TB
180 TB

There are a number of ways to speed up performance by write caching in onboard memory, but the key is to provide persistence for cached data to ensure there is no data loss. HGST utilizes its media cache technique, and Seagate's retort is its new Advanced Write Caching technique. There are fundamental differences to the two approaches (Seagate utilizes NOR flash), but Seagate's approach is designed to offer the highest random write performance on the market -- a staggering 100 percent increase over its previous-generation models.

IOPS metrics are standard fare for SSD specifications, but HDD vendors shy away from listing them (it is the key weakness of HDDs). I spend a lot of time studying enterprise HDD data sheets for our product evaluations, and honestly, I cannot recall anyone listing random read/write IOPS in any of them. Seagate must be very confident in its new approach, as it is touting its 164/342 random read/write IOPS on the Enterprise Capacity data sheet. We have clocked the HGST He8 at 325 random write IOPS, so its obvious competition has returned to the capacity segment.

Seagate released the power specifications of its drives under operation, and they are still higher than HGST's average power draw of 7.4 Watts. Seagate may attempt to pop the helium power-savings balloon by offsetting it with a lower up-front cost (helium drives tend to command a premium over other drives), but we do not have official pricing as of yet.

Enterprise Capacity 8 TB

The Enterprise Capacity 3.5 HDD satisfies the toughest workloads in 8-16 bay applications, such as hyperscale/cloud, scale-out, analytics, RAID, SAN, NAS and DAS with its 550 TB yearly workload rating. The six-platter drive spins 1.33 TB per platter (33.3 percent density increase) at 7,200 RPM and comes in both 12 Gbps SAS and 6 Gbps SATA flavors. 

Seagate increased the MTBF to 2 million hours, in comparison to the 1.4 million hours with the previous model, and also increased cache from 128 MB to 256 MB. The drive also has the notable addition of 2M of NOR flash for its Advanced Write Caching feature, which powers the 100 percent increase in random write speed. Seagate also offers a 15 percent increase in sequential speed over competing 8 TB HDDs (HGST He8). The Enterprise Capacity is only offered at the 8 TB capacity point.

Enterprise NAS HDD

The Enterprise NAS HDD also spins at 7,200 RPM and is geared for 4 to 16 bay NAS environments. The SATA 6 Gbps drive features a 300 TB yearly workload, but a relaxed 1.4 million hour MTBF. The Enterprise NAS HDD also features 1.33 TB per platter, but it doesn't include the Advanced Write Caching feature. The Enterprise NAS HDD comes in multiple capacity points that span 2 to 8 TB.

Kinetic HDD

The 8 TB Kinetic HDD utilizes an Ethernet connection (single or dual) in tandem with the Kinetic object storage protocol to reduce the amount of infrastructure required in enterprise deployments. Kinetic is gaining traction with a recently-announced Kinetic Open Storage Project group and more enclosures coming to market, including Seagate's own Kinetic OneStore 5U enclosure. The OneStore enclosure features 84 drive bays and packs up to 672 TB per enclosure, or 5.3 PB per rack. The enclosure will be available in November 2015. 

The kinetic drive utilizes a drive-managed SMR implementation that is transparent to the host. It features 128 MB of standard DRAM cache, and 1024 MB of Armada Cache. The drive features a low workload rating of 180 TB per year, which reflects the intended use-cases of object storage environments, hyperscale and scale-out bulk storage arrays.

All of the drives are currently sampling to customers, and general availability is slated for later this year.