The WD Re addresses the need for bulk storage of cold data, and brings many enterprise-class features to ensure data integrity. The inclusion of both SAS and SATA standards, and at 6Gb/s and 3Gb/s for good measure, allows the implementation of these HDD's into a wide range of solutions.
In our testing, the WD Re delivered exceptional performance in pure write environments, though it did lag behind the competition in read workloads. The 4K and 8K test results were encouraging in random environments, and the 128K sequential tests were particularly impressive in our mixed read/write testing.
The WD Re did have an overall higher power consumption than the rest of the test field, but when measured from an efficiency standpoint in the IOPS to Watts testing, the WD Re scored well in comparison to the rest of the test pool.
A bright spot in the performance of the WD Re was the excellent latency, which scored in tight groups with little variability. With the 7K4000 leading in many performance tests, it was surprising to see the WD Re best it at latency consistency. Some of this is due to the almost bimodal latency performance of the 7K4000.
The WD Re brings a number of features to the table that makes it an attractive solution. The wide range of connectivity options make it deployable into numerous scenarios, and the option of an SED (Self Encrypting Drive) option also provides a means of enhanced data security. This can be beneficial over the course of the drives' life, and during retirement or repurposing of the drive. Features such as crypto erase and the ATA sanitize command can effect speedy data destruction that can save time and money by eliminating the need for physical destruction of the drive.
While the 1.2 million hour MTBF is merely middle of the road for this class of HD, and under the 2.0 million hours of the 7K4000, the WD Re does have the best error reduction technology. This is evidenced by the 10E16 non-recoverable read errors per bits read rating, which is well in excess of the standard 10E15 for this class of HDD.
Overall, there is a delicate balance of a number of factors to take into consideration. Reliability, performance, latency and power consumption are all factors to weigh when choosing the correct solution for the workload. The WD Re brings several features to bear, such as TLER, dynamic fly height technology, NoTouch ramp load, multi-axis shock sensors, StableTrac and dual actuator technology that all combine to provide the enhanced functionality of a drive with an excellent 10E16 rating.
Unfortunately, the 7,200 RPM 4TB HDD lineup is very competitive, and the pricing of the WD Re can be prohibitive when compared to other solutions. This can be a premium for the enhanced reliability borne from the extensive testing and inter-operability qualifications, but many will opt for higher performance solutions at a lower price.