At the end of a long and complex product evaluation, it is best to bring things back to simplicity. One of the major motivations for deploying Seagate Turbo SSHD's is the hassle-free installation of the drives into standard equipment. There are no special drivers or any type of management required. This simplicity will bring about huge returns in existing infrastructure. Installing 10 SSHDs adds a 320GB shot of flash acceleration into the server with absolutely no hassle; you simply install the drives. The SSHD occupies the middle ground between SSD's and HDD's, providing a single device that handles caching and tiering automatically.
It's that sort of 'problem solved' mentality that led Seagate down the path to SSHD's in the first place. With lackluster performance increases from standard approaches, and SSDs encroaching upon the performance segment in client and enterprise environments, Seagate decided to marry the speed and efficiency of the SSD with the capacity of an HDD. The initial foray into the client space has resulted in such wild success that Seagate quit producing standard 2.5" HDD's in favor of only offering SSHD's.
In our standard testing, we witnessed appreciable gains with 100% LBA random read workloads. These same gains also transferred over to our mixed workloads. The combination of partially cached read data, and faster random write speeds resulting from the alleviation of head movement, delivered a large advantage over the standard HDD. The partially cached results we received, even when testing with full-span read/writes, were outstanding. Applications often rely upon tight groupings of data that will result in significantly enhanced performance, beyond what we have demonstrated with our full span testing.
In our targeted testing, we witnessed just how fast the SSHD can be when data is cached in its entirety. It is possible to attain results well above any existing HDD with a top speed of 8,800 IOPS from the NAND cache layer. Short-stroking typical HDD's can deliver performance gains, but also adds to the cost of deployment. Not only are SSHD's much faster than short-stroking, they deliver a lower TCO. The Dollar to IOPS ratio of the SSHD will easily rival that of short-stroked HDD's.
The reliability of the SSHD is also within expected norms, with a two million hour MTBF and a .44% AFR. The extra layer of NVC cache also adds the option for expanded power-loss protection not offered with typical enterprise HDD's. FIPS 140-2 functionality and secure encryption round out the enterprise-class features, while the five-year warranty should allay any fears of utilizing this relatively 'new' technology.
While the 32GB of eMLC may seem small compared to the overall size of the SSHD, the fact is that most hot data, and metadata, occupies a small portion of the entire storage space. By intelligently caching the most relevant and hard-to-access blocks, and allowing the platters to handle the data access they excel at, the Turbo SSHD can deliver big gains in application performance.
We expect the maturation of the SSHD platform to accelerate rapidly, with larger portions of flash making their way into numerous types of enterprise-class HDD's. Seagate's AMT technology is truly revolutionary and looks to help redefine the limits of enterprise HDD performance in a cost-conscious manner.
Update: Unless otherwise noted performance results for the Turbo SSHD are conducted over 33% of the LBA range to highlight caching performance.