In a rather unexpected move, Western Digital introduced its first dual actuator hard disk drives (HDDs) on Monday, matching its competitor Seagate's impressive Exos drives that use similar tech. The dual actuator Ultrastar DC HS760 20TB HDD (opens in new tab) builds upon the proven single-actuator Ultrastar DC HC560 drive, but doubles its sequential read/write speeds to the types of speeds we see with SATA SSDs and also nearly doubles its random read/write performance. The key advantage of the new HDD for hyperscale cloud data centers is increased IOPS per terabyte.
Two independent actuators in the drive work in parallel, offering up twice the sequential throughput (up to 582 MB/s), which is on par with a SATA SSD in throughput, and 1.7X higher random performance than a single-actuator HDD (still not comparable to an SSD). WD also claims the drive consumes up to 37% less power than two separate hard drives. For some reason, Western Digital did not publish detailed specifications of the product, though we hope to see a datasheet soon.
The Ultrastar DC HS760 20TB dual actuator hard drive uses Western Digital's third generation OptiNAND platform, featuring nine 2.2TB ePMR (energy-assisted perpendicular magnetic recording technology) platters and NAND flash cache to store metadata and write cache data to boost performance and increase areal density.
The Ultrastar DC HS760 drive is accessed via single-port SAS and presents itself as two 10TB logical unit number (LUN) SAS devices. Since the logical HDDs are independently addressable, they need software tweaks on the host side. To that end, not all data centers can use the new drive.
Western Digital's Ultrastar DC HS760 20TB HDD offers higher capacity than Seagate's dual-actuator Exos 2X18 18TB hard drives, but Seagate also offers its drives with a SATA interface, which makes it compatible with a wider range of customers.
As the capacity of HDDs increases, their IOPS-per-TB random read/write performance drops, which makes it harder for data centers to maintain their quality of service. Dual-actuator HDDs solve this problem by significantly increasing the performance of HDDs, albeit at the cost of somewhat higher power consumption.
Like other Western Digital Ultrastar drives, the DC HS760 20TB has a five-year warranty and is intended to work in 24/7 environments. Each LUN is designed to handle up to 500TB per year, slightly lower than the 550TB-per-year workload of typical data center HDDs.
Western Digital does not disclose the pricing of its dual actuator HDDs, but they will naturally be more expensive than single-actuator hard drives. Also, since these storage devices are designed for data centers, their actual price will depend on many factors, such as volume and established or new long-term agreements.
It's to where, even with the overhead, I wouldn't be surprised if we see USB 4 instead.
I just dropped two WD Red 20TB drives in my servers this month and have more upgrades to do over the next couple years. I can't wait for drives like this to increase my speeds. I have in excess of 97TB (formatted space ) over a couple drive pools of 44TB and 43TB respectively on seperate servers for data redundancy (one hot one cold in case of hacks, bitrot and/or system damage). I would love to cut down on the number of smaller drives while increasing my overall capacity. I have some 2-8TB drives that I could use in my wifes rig for local game/file storage when I rebuild hers this spring? I hope. Both enjoying photo/video editing, backing up analog and digital media like VHS/DVD/HDDVD/Bluray/records/CDs/MP3s etc, not to mention our steam game back-ups we can chew through storage space as fast as you give it to us.
Honestly that would be great in the long term. HDDs are only good for large data pools not worth putting on solid state, back-ups, NAS etc. For most home users HDDs are becoming very niche and those users like myself who do use them would benefit from the switch to SAS though I'd likely make such a transition slowly as these larger drives are not cheap...
When your running 30+ TB data sets that need backing up or recovering those file transfers can literally take days. Anything to speed things along is outstanding if not a reason to upgrade my whole house to 5GB or better networking compared to my mix of 1GB/2.5GB I am running now.
There are U.2 ports on some mobo, but it's mostly servers and high-end workstations that use it.
A shame, because the M.2 standard on consumer PC is an idiotic redneck solution.
I feel like I'm in the dark ages when installing or switching out an M.2 SSD that requires a screwdriver.
U.2 also allows you to install multiple SSD drives on workstation mobo. Which of course you can't do with consumer M.2 mobo, because you would end up with a giant mobo.
That's why you no longer see people experimenting by putting SSD in RAID 4 to get ridiculous speeds, like people did with SATA SSD. You simply can't do that with M.2 SSD, there's no mobo that have 6+ M.2 slots, but there's plenty of workstation solutions with many U.2 slots.
The best selling SSD are still SATA, likely because you can switch them out so easily.
U.2 is SATA 4.0 really, and it is successful on workstations and servers because you can change out a drive in 2 seconds. But apparently they think consumers prefer diving into their case with a screwdriver like an idiot instead of simply plugging something in and out.
U.3 Ports are:
Space Efficient on the MoBo edge ( 1x U.3 Port = 2x Vertical Stacks of SATA Ports via adapter) in terms of how many HDD's can be supported.
Supports SATA, SAS, & PCIe through one Universal connector.
Less Material to use, gives you more drive connection options and more drives to be connected.Also, modern SSD's need to start using the 1.8" HDD form factor as "Their new standardized Form Factor".
A 5 mm thick 1.8" HDD, reused as the modern SSD standard & using standard SAS/SATA/nVME over PCIe U.3 connector is perfect IMO.
The PCB area is for a 1.8" HDD form factor is up to 3600 mm² on one side of the PCB.
A 30110 M.2 drive has 3300 mm² on one side of the PCB.
That's MORE than enough PCB real estate for optimal routing.
At 1.8", the form factor is compact enough to slip into your pocket
It's smaller than a pack of Bicycle Playing Cards, slightly larger than a PS2 Memory Card.
Thinner than both of those items at 5 mm thick.
While HDD's should retain the 3½" & 2½" form factors as their primary domain.
Also, it's great for WD to finally step into the Multi-Actuator Arms race.
The race is on to satiate the bandwidths of SATA/SAS/nVME over PCIe.
How many independent actuators can you get to.
Obviously, the ultimate goal is every actuator arm being fully independent, that would be "AWESOME".
The combined throughput of that would be CRAZY HIGH.
Now, they need "Built in RAID 0" at the controller level to make it easily useable for every day consumers.
It's the one connector that should rule them all.
I TOTALLY agree. M.2 was designed for LapTop mobile, not for everyday goofs to mess around with.
Also, the M.2 connector has a "Mating Cycle Rating = 50 Cycles" of Inserting & Removing
The SATA/SAS connector has a "Mating Cycle Rating = 10,000 Cycles" of Inserting & Removing
One is obviously more durable than the other while doing the exact same thing.
It's IDIOTIC to depend on M.2 for everything when it was supposed to be a niche LapTop drive.
I prefer SATA/SAS Backplanes myself, far more user friendly and requires only a proper one time setup.
It offers a FAR better user experience once you have to swap drives for any reason.
U.3 to the rescue, replace the SATA ports on the right edge of the MoBo with U.3.
There are Add-in cards that can raid together M.2 slots if you really cared about it, but realistically, I'd rather not use those if possible.
Also because the controller & interface for them are dirt cheap.
U.3 is the proper successor.
Probably won't see U.3 on consumer either. Maybe it will make it into Threadripper and Sapphire Rapids boards, at least in the OEM space.
M.2 is the way it is because it is cheap, and nothing will replace cheap. Not all boards require screws, the nicer boards have toolless NVME installation. Also, how often you changing these things out?
You can always get a SAS controller or even a U.2 expansion board.
IMO, it's pretty clever to present these as independent drives. This lets the host manage them in a much more natural way.
One nagging concern I can't quite shake is the issue of one actuator interfering with another, by the force it exerts on the drive. I guess you could control for this by preventing an actuator from moving while the other is reading or writing. Another idea I had was to add weights that counter-rotate around the same axis, in order to cancel out the movement. But that seems bulky and a bit clunky.