Seagate Introduces SSHD Lineup with Dual Mode NAND Cache

Subject: Storage | March 8, 2013 - 09:20 AM |
Tagged: sshd, solid state, Seagate, Intel SRT, cache, adaptive memory

Following the announcement that the company would be axing 7200 rpm notebook drives, Seagate has introduced its third generation hybrid hard drives. The new Seagate Solid State Hybrid Drives (SSHD) will initially launch with two notebook drives and a single desktop-sized drive. The hybrid drives will combine a spinning platter drive with 8GB of NAND flash with Seagate’s Adaptive Memory tech that will reportedly cache reads as well as writes.

The 2.5” notebook SSHDs include a 7mm model that combines 500GB of mechanical storage and 8GB of Adaptive Memory cache. This model will retail for around $80. There will also be a slightly larger 9.5mm  with 8GB of cache and 1TB mechanical hard drive capacity. The 1TB model utilizes two 500GB, 5400RPM platters and will retail for just under $100.

Seagate SSHD.jpg

The desktop SSHDs come in 3.5” form factor and will initially use 7200 RPM platters.  Seagate will offer up to 2TB of mechanical storage with its SSHDs and 8GB of NAND flash for caching.  Seagate claims that its desktop SSHD is up to four times faster than other mechanical hard drives, (according to PC Mark Vantage) which is likely due to the Adaptive Memory technology caching frequently used data on the flash memory and the use of 1TB platters. The 1TB and 2TB SSHD will cost around $100 and $150 respectively. Naturally, the SSHDs will carry a small premium over traditional mechanical hard drives. They will still be much more price-efficient than Solid State Drives for the storage offered (though I would still like to see a larger NAND cache).

Interestingly, Tech Report was able to glean a few more details about Seagate’s third generation hybrid drives. Reportedly, the drives will be capable of writing as well as reading to/from the NAND cache. That is a major step up from previous generation’s which limited the drive’s flash storage to a read-only cache. Seagate has reportedly built the drives such that they will have enough capacitance to flush the write cache in the event of a power failure (so that you will not lose any data). The dual mode NAND term stems from Seagate’s ability to use SLC for boot data and the write cache and address the remaining NAND as MLC flash. Unfortunately, details are scarce on how Seagate is doing this.

The SSHDs will come with three year warranties, but Seagate has rated the NAND flash at a lifespan of at least five years. In an neat twist, Seagate is also allegedly working on another SSHD implementation that will combine a mechanical hard drive and a larger NAND cache. However, the flash memory will be managed by Intel’s Smart Response Technology instead of Seagate’s own Adaptive Memory tech (which doesn't need additional drives, unlike SRT). Using the port multiplexing aspect of the SATA spec, Seagate will be able to put both drives into a single 3.5” form factor hybrid drive. Admittedly, this is the Seagate SSHD that I am most excited about, despite the fact that it’s also the drive I know the least about. I’m interested to see what kind of performance Seagate can wring out of the larger cache!

Source: Seagate