As with any purchasing decision, there is always the question of whether or not to make the jump to the next level of performance. The advent of a new class of consumer HDDs geared for NAS usage has blurred the line between consumer and nearline/enterprise HDD's. We have conducted full product evaluations of both the WD Red and the WD Se as single units, and today we will test them in RAID configurations.
WD's NAS HDD market segmentation is a perfect example of the shrinking difference between top-of-the-line nearline/enterprise HDD's and consumer hardware. The WD Red series is geared for the SMB and SOHO crowd with 1-5 bay NAS units. For a small price premium, customers can acquire the higher rated WD SE series of HDDs, geared for SMB (Small/Medium Business) and large enterprise applications with 6-12 bays.
In many cases, users looking for the next level of performance from their 1-5 bay NAS units turn to the WD Se. Both the WD Se and the WD Red share many characteristics that begin with the SATA 6Gb/s connection. They also share the same 64MB of cache and a bit error rate of 1 per 10E14. Both HDD's are designed for 24/7 use, and the duty cycle of a NAS HDD experiences many transitions from various idle states to active use. This is reflected in the robust 300,000 cycles Load/Unload cycle ratings for both drives.
One of the immediate performance improvements when making the jump from the Red to the Se is the difference in platter speed. The Red utilizes WD's IntelliPower technology, which many speculate alters the speed between 5,400 and 5,900 RPM's. The 7,200 RPM advantage leads to enhanced speed from the Se, but also an increase in power consumption. The Red consumes a peak of 4.5 Watts active, while the Se has a higher active consumption of 9.5 Watts. The noise of NAS HDD's can become a bit of a distraction in home user environments, and the WD Red has a lower decibel rating of 24, in contrast to the 28 offered by the Se.
The Se has a higher tolerance to heavy workloads, with up to 180 TB a year falling within its endurance envelope. The Red supports 120-150 TB a year, which is fine for most home users. Interestingly enough, the Red actually has a higher MTBF rating of one million hours, while also having a much shorter warranty period of three years. The WD Se has an MTBF rating of 800,000 hours, yet a longer warranty period of five years.
The disparity between the MTBF and warranty periods from both drives likely stems from the test environments during qualification. In larger rack environments, which the Se is designed for, there is a tremendous increase in vibration and heat. Vibration is introduced by other drives in the rack, and with the intended purpose being 6-12 drive racks, the drives are subjected to more vibration and heat. The drives are also tested with their respective workloads, and with the Se having a higher 180TB rating, the drive endures a more stringent test regimen.
In similar environments, the Se will outlive the Red, as reflected in the warranty period. The warranty period of a NAS is important, many users simply want to buy several high-quality drives, configure them in the NAS, and forget them for the next several years. For many the higher warranty period of five years for the Se, and the enhanced speed, make them an attractive solution.
Today we will test the 4-drive RAID performance of the WD Se and the WD Red series head-to-head in both RAID 0 and RAID 5 configurations.