Today Western Digital made a rather significant announcement in the field of HDD technology. We’ve previously talked about upcoming ways to increase the density of HDD storage, with the seeming vaporware Heat Assisted Magnetic Recording (HAMR) forever looming on the horizon, just out of reach.
WD, like others, have been researching HAMR as a possible way of increasing platter densities moving forward. They were even showing off prototypes of the technology back in 2013, but a prototype is a far cry from a production ready, fully reliable product. Seagate had been making stronger promises of HAMR, but since we are already 5 years into their 10-year prediction of 60TB HAMR HDDs (followed by further delays), it's not looking like we will see a production ready HAMR HDD model any time soon.
Ok, so HAMR is not viable for now, but what can we do? Seems WD has figured it out, and it's a technology they have been kicking around their labs for nearly a decade. Above we see the PMR limit of ~1.1 Terabits/square inch. SMR pushes that figure to 1.4, but we are running up against the so-called 'writeability limit', which is the point at which the write head / magnetic field is too small to overcome the paramagnetic threshold of the smaller magnetic domains of higher density media. We are used to hearing that the only way to raise that limit was to heat the media with a laser while writing (HAMR), but there is a different / better way – Microwave Assisted Magnetic Recording, or MAMR for short.
Don't let the 'microwave' part of the term fool you – we are not microwaving the media with sufficient energy to actually heat it. Instead, we are doing something *way* cooler. The slide above shows how smaller grain size (higher density) requires a stronger write field to reach sufficient energy levels to reliably store a bit of data. Now check out the next slide:
This is a lot to grasp but allow me to paraphrase greatly. Imagine a magnet with a north and south pole. If you came along with a stronger magnet and attempted to reverse its polarity by directly opposing the currently stored state, it's generally difficult to do so. Current HDD tech relies on the field being strong enough to overcome the stored polarity, but MAMR employs a Spin Torque Oscillator, which operates at a high enough frequency (20-40 GHz) to match the ferromagnetic resonance of the media. This causes a precession of the stored field (like a gyroscope) and tilts it about its vertical axis. This resonance adds the extra energy (in addition to the write field) needed to flip the field to the desired direction. What's amazing about this whole process is that thanks to the resonance effects, the STO can increase the effectiveness of the write field 3-4x while only consuming ~1/100th of the power compared to that needed to generate the write field. This reduction in the damping constant of the media is what will enable smaller magnetic domains, therefore higher platter densities in future MAMR-equipped HDDs.
One of the best things about this new tech is that it is just a simple addition to all of other technologies already in place today. Western Digital was already making their drive heads with an advanced 'damascene' process, silently introduced about three years ago. To oversimplify the description, damascene is a process that enables greater physical precision in the shape of the head, which helps increase density. What makes this process a bigger deal now is that it more easily enables integration of the Spin Torque Oscillator into the head assembly. Aside from this head-level change and another pair of leads to provide a very small drive current (~1-2mA), every other aspect of the drive is identical to what we have today. When it comes to a relatively radical change to how the writing can be accomplished at these upcoming higher densities, doing so without needing to change any of the other fundamental technologies of the drive is a good thing. By no change, I really mean no change – MAMR can be employed on current helium-filled drives. Even SMR.
Western Digital also slipped in another announcement, which is the shift from the older style 'nested actuator' (introduced with 2TB HDDs back in 2009), to a newer 'micro-actuator'. The newer actuator moves the articulation point much closer to the head compared to the previous technology, enabling even finer head tracking, ultimately resulting in increased track pitch. WD currently sits somewhere around 400 tracks per inch (TPI), but they hope to reach 1 million (!) thanks to this new tracking combined with MAMR and improved media chemistry.
Now this doesn't mean we will see a sudden influx of 40TB HDDs hitting the market next week. WD still has to scale up production of STO-enabled heads, and even after that is complete, the media technology still needs to catch up to the maximum capabilities of what MAMR can achieve (creating smaller magnetic domains on the disk surface, etc). Still, it's nice to know that there is a far simpler way to flip those stored bits around without having to resort to HAMR, which seems to be perpetually years away from production. Speaking of which, I'll leave you with WD's reliability comparison between their own HAMR and MAMR technologies. Which would you choose?
Oh yeah, and about that supposed SSD vs. HDD cost/GB crossover point. It may not be as soon as we previously thought:
Full press blast appears after the break.
WESTERN DIGITAL UNVEILS NEXT-GENERATION TECHNOLOGY TO PRESERVE AND ACCESS THE NEXT DECADE OF BIG DATA
Company Builds on its Leadership of Delivering Industry’s Highest Capacity Hard Drives with Demonstration of Breakthrough Innovation on Microwave-Assisted Magnetic Recording Technology
SAN JOSE, CA — Oct. 11, 2017 — At its “Innovating to Fuel the Next Decade of Big Data” event today, Western Digital Corp. (NASDAQ: WDC) announced a breakthrough innovation for delivering ultra-high capacity hard disk drives (HDDs) to meet the future demands of Big Data with proven data center-level reliability. The event, held at the company’s headquarters in Silicon Valley, included a demonstration of the world’s first microwave-assisted magnetic recording (MAMR) HDD and presentations from company executives and the inventor of MAMR technology, Professor Jimmy Zhu from Carnegie Mellon University. The company also showcased advancements in micro actuation and Damascene recording head technology. Western Digital expects to begin shipping ultra-high capacity MAMR HDDs in 2019 for use in data centers that support Big Data applications across a full range of industries.
“As the volume, velocity, variety, value and longevity of both Big Data and Fast Data grow, a new generation of storage technologies are needed to not only support ever-expanding capacities, but ultimately help our customers analyze and garner insights into our increasingly connected universe of data,” said Mike Cordano, president and chief operating officer at Western Digital. “Our ground-breaking advancement in MAMR technology will enable Western Digital to address the future of high capacity storage by redefining the density potential of HDDs and introduce a new class of highly reliable, ‘ultra-high capacity’ drives. We have a proven track record for identifying, investing in and delivering advanced technologies that create new product categories and enable the world to realize the possibilities of data. Five years ago we introduced our HelioSeal®, helium-filled drive technology. Since then, we have shipped more than 20 million helium drives. That type of leadership and innovation continues today and we aim to leverage it well into the future.”
MAMR is one of two energy-assisted technologies that Western Digital has been developing for years. The company recently innovated a breakthrough in material and process that provides the required reliable and predictable performance, as well as the manufacturability to accelerate areal density and cost improvements to an estimated average of 15 percent per year. Developments in the other energy-assisted technology, specifically, heat-assisted magnetic recording (HAMR), present new material science and reliability challenges that are not a factor in MAMR. Only MAMR demonstrates the reliability and cost profile that meets the demands of data center operators.
At the heart of the company’s innovation breakthrough is the “spin torque oscillator” used to generate a microwave field that increases the ability to record data at ultra-high density without sacrificing reliability. Western Digital’s innovative MAMR technology is expected to offer over 4 terabits-per-square-inch over time. With sustained improvements in recording density, MAMR promises to enable hard drives with 40TB of capacity and beyond by 2025, and continued expansion beyond that timeframe.
“Western Digital’s demonstration of MAMR technology is a significant breakthrough for the hard disk drive industry,” said John Rydning, research vice president, Hard Disk Drives, IDC. “Commercialization of MAMR technology will pave the way to higher recording densities, and lower cost per terabyte hard disk drives for enterprise datacenters, video surveillance systems, and consumer NAS products.”
Western Digital’s MAMR technology is the latest innovation to significantly improve areal densities. It builds upon a number of other leading innovations from the company. In addition to HelioSeal helium-filled drive technology, MAMR also builds upon the company’s micro actuation and recording head manufacturing technologies. Western Digital’s advanced micro actuation technology for data center applications enables hard drives to accurately and reliably position magnetic heads for writing and reading at ultra-high densities. The company’s head manufacturing operations are the only internal supplier to utilize Damascene processing to manufacture heads with the precise tolerances and complex structures required for reliable and cost-effective recording at ultra-high densities. The Damascene process also provides the capability to embed the spin torque oscillator that enables the manufacturing of MAMR heads. The combination of these technologies deliver superior total cost of ownership (TCO) across all sizes of cloud and enterprise data centers.
The demonstration of Western Digital’s MAMR technology is the latest achievement in decades of HDD leadership from the company, including over 7,000 issued patents in HDD technology, on-going helium-enabled HDD technology advancements – as highlighted by the recent introduction of the world’s first host-managed shingled magnetic recording (SMR) technologyenterprise-class 14TB hard drive – and a long history of world’s firsts in multi-disk design.
For further information on Western Digital MAMR technology, go to http://innovation.wdc.com.
For press images and materials, visit http://bit.ly/2kHsNgf
About Western Digital
Western Digital creates environments for data to thrive. The company is driving the innovation needed to help customers capture, preserve, access and transform an ever-increasing diversity of data. Everywhere data lives, from advanced data centers to mobile sensors to personal devices, our industry-leading solutions deliver the possibilities of data. Western Digital data-centric solutions are marketed under the G-Technology, HGST, SanDisk, Tegile, Upthere and WD brands.