AFAICT, the Black WD1003FZEX is an AF drive whereas the RE WD1003FBYZ is non-AF. This means that the Black should have an 11% faster transfer rate, all other things being equal. The Black WD1002FAEX has a sustained transfer rate of 126MB/s which is on par with a non-AF drive. All three appear to have two 500GB platters.
I notice that the Black spec sheet talks about Vibration Control Technology. Perhaps this explains the two extra shock sensors. That said, I don’t understand how VCT differs from RAFF.
Also, I see that the enterprise drives have dual actuators, but that’s only for the 2TB+ models. There is also mention of a “multi-axis shock sensor”, but it’s not clear whether it refers to the smaller shock sensor adjacent to the SDRAM. This smaller sensor is also present on the Black. There is a component at U7 which I don’t recognise, but it appears to be present on both the Black and RE drives. The other difference is the load/unload ramp on the RE models.
WD Black Series Spec Sheet:
http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-771434.pdf
WD Re Series Spec Sheet:
http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-771444.pdf
As for Stabletrac, AFAICT WD have added a single screw, called it Stabletrac ™, and then got their marketing department to beat it up.
http://www.wdc.com/en/company/pressroom/releases/?release=a2e49df5-67fe-4437-b4f0-60ef1af650fb
“Used on WD high-capacity hard drives and to further ensure reliability, WD’s StableTrac technology was incorporated. StableTrac’s motor shaft is secured at both ends to reduce system-induced vibration and stabilize platters for accurate tracking during read and write operations. Most current hard drive designs feature motors that are only attached on the bottom of the hard drive, which can cause missed read revolutions. StableTrac allows end-user data to be retrieved fast without missing revolutions.”
Stabletrac video demo:
http://www.wdc.com/en/flash/index.asp?family=stabletrac
WD Scorpio Blue Mobile Hard Drives Spec Sheet:
http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-771437.pdf
StableTrac - “Motor shaft affixed to the baseplate and top cover stabilizes platters for accurate tracking during read and write operations, yielding higher drive data throughput in harsh shock and vibration environments. Supporting the top cover with the shaft also increases robustness to pinch forces.”
What really surprised me is the absence of “3D Active Balance Plus” in the enterprise-class HDDs. Apparently this technology is only present in the consumer grade Reds.
NAS brochure:
http://www.wdc.com/wdproducts/library/Flyer/ENG/2178-800027.pdf
Red - Personal/SOHO NAS HDD
Se - Enterprise capacity NAS
Re - Enterprise performance NAS
Red - Intellipower, NASware 2.0, 3D Active Balance Plus, Small-NAS f/w
Se - 7200 RPM, TLER, StableTrac, RAFF, Enterprise-class f/w
Re - 7200 RPM, TLER, StableTrac, RAFF, Enterprise-class f/w
I couldn’t find what I was looking for on WD’s web site, but I found the following review:
http://www.pcper.com/reviews/Storage/Western-Digital-Red-3TB-SATA-SOHO-NAS-Drive-Full-Review/Specs-Testing-Methodology-an?page=2
According to WD …
“3D Active Balance Plus - Our enhanced dual-plane balance control technology significantly improves the overall drive performance and reliability. Hard drives that are not properly balanced may cause excessive vibration and noise in a multi-drive system, reduce the hard drive life span, and degrade the performance over time.”
According to the reviewer …
“I used WD’s blurb for that last one, but as a translation - this is HUGE. There is a system of movable counterbalances installed in the spindle motor hub assembly. These weights are free to shift, and with the drive at speed, those parts will settle in positions which act to actively counter vibrations. WD had a video showing this, but I prefer a simpler automotive-related analogy, which I will present in the form of this video: Western Digital’s system is much more complex than the simple example above, as it functions both axially and radially. This is the equivalent to obtaining a continuous and automatic dynamic balance of the wheels on your car. While that would give you a smooth ride, WD’s implementation gives you a silent and non-vibrating drive. This works so well that all I can hear from a running Red is the faintest sound of air turbulence across the spinning platters.”
AIUI, we have a consumer grade 5400 RPM (“IntelliPower”) HDD with enterprise-class spindle motor balancing, whereas the enterprise grade 7200 RPM HDDs are limited to a Stabletrac ™ screw. Surely that can’t be right?
BTW, I couldn’t find WD’s 3D Active Balance Plus video, but perhaps I didn’t search for it in the right place.
