Western Digital MAMR Tech Pushes Future HDDs Beyond 40TB

Subject: Storage | October 11, 2017 - 11:16 PM |
Tagged: western digital, wdc, WD, STO, Spin Torque Oscillator, SMR, PMR, Microwave Assisted Magnetic Recording, microwave, MAMR, HAMR, FMR

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.

HAMR strike delayed until 2018

Subject: General Tech, Storage | December 28, 2015 - 07:21 PM |
Tagged: HAMR, delay

We had hoped to see Heat Assisted Magnetic Recording sometime in 2017 but that goal has proved to be optimistic and 2018 is now the current expectation for its arrival.  This technology will allow storage densities higher than 1.5 Tb/in2 but is not quite ready for primetime at the moment.  Prototypes do exist and some are being sent to customers to test the reliability and performance of drives in real life test scenarios.  The drives will be slower than flash based storage of course, however when it comes to storage density spinning rust still holds the crown and will continue to do so for some time.  You can refresh yourself on the technology by following the links in this post and read more about the delays over at Slashdot.


"Unfortunately the hard disk drive industry is not ready to go live with Heat-assisted Magnetic Recording (HAMR). The technology is yet not reliable enough for mass production. Over the years, producers of hard drives, platters and recording heads have revealed various possible timeframes for commercial availability of drives with HAMR technology. Their predictions were not accurate."

Here is some more Tech News from around the web:

Tech Talk

Source: Slashdot

Getting heavy into HAMR's theory

Subject: General Tech | March 24, 2015 - 12:43 PM |
Tagged: HAMR, science

If you are curious just how Heat Assisted Magnetic Recording is able to increase the storage densities of your HDDs then this post at Nanotechweb and the linked article will make a great read.  They deal with how plasmonic near-field transducers, which will oscillate in time with the frequency of a light source, as long as the light source's frequency is equal to or less than the plasma frequency.  This causes heat but nowhere near as much as if the light was used directly and so avoids potentially damaging hotspots.  They also delve into the materials which are being tested to provide more efficient heat transmission; it is not light reading but it is very informative for those curious about HAMR's development and future.


"Heat-assisted magnetic recording (HAMR) is a leading technology for advancing hard-disk-drive areal density beyond 1 Tb/in2. To reduce the magnetic coercivity, near-field transducers (NFTs) made of plasmonic nanostructures are used."

Here is some more Tech News from around the web:

Tech Talk

Source: Nanotechweb

Seagate is still HAMRing away at improved HDD storage density

Subject: General Tech | December 9, 2014 - 01:26 PM |
Tagged: HAMR, Seagate, hdd, TDMR

Seagate has been talking about HAMR for many years now but is finally getting close to being able to provide a working product.  Currently they use perpendicular magnetic recording which should reach an areal density of 850/900Gbit/in2 in the coming year with a shingled version hitting 1Tbit/in2.  Shingled platters store data in slightly smaller and overlapping tracks reminiscent of a shingled roof.  In 2016 Seagate predicts the arrival of TDMR which will start at the same density as shingled PMR with an increase to 1.3Tbit/in2 when set up in a shingled format.  2017 is the tentative date for the arrival of the brand new technology and as of now Seagate is predicting an aureal density somewhere in the neighbourhood of 2Tbit/in2.  The performance will never match that of flash based drives but the cost per gigabyte will be far more attractive for those who have more of a need to store large amounts of data than to have high speed access.  Check out more at The Register.


"We have better visibility into Seagate’s view of the ending of the current perpendicular magnetic recording (PMR) era. The ending is delayed by narrowing the tracks so as to cram more of them on a platter. This is called two-dimensional magnetic recording (TDMR) and should arrive in 2016."

Here is some more Tech News from around the web:

Tech Talk

Source: The Register

HAMR's twin brother

Subject: General Tech | November 21, 2013 - 12:46 PM |
Tagged: HAMR, western digital

In the race to increase the areal density of HDDs the tech to work towards is currently Heat Assisted Magnetic Recording as the current shingle technique has helped us increase storage capacity by a small amount but not enough to be the next evolution.  Seagate announced their strategy to develop HAMR technology over a year ago but we have yet to see a prototype.  Western Digital has just shown off their version of HAMR to a bevvy of journalists, not including The Register, with a working prototype.  WD predicts densities reaching 4 terabits per square inch, making an 8TB 2.5" drive a possibility but they have not predicted a release date yet.


think bigger than this

"In September 2012, Seagate boss Steve Luczo gave a presentation using a HAMR technology disk drive. Now, more than a year later, a WD exec has done the same with the company's own HAMR tech drive."

Here is some more Tech News from around the web:

Tech Talk

Source: The Register

HAMRs, Shingles and SSD cached HDDs; size versus speed

Subject: General Tech | August 8, 2013 - 01:58 PM |
Tagged: HAMR, SMR, cache, hdd, Seagate, western digital, hgst, helium

Enthusiasts are wholeheartedly adopting SSDs for their storage media of choice with HDDs relegated to long term storage of infrequently accessed storage.  For SMB and enterprise it is not such an easy choice as the expense to move to a purely SSD infrastructure is daunting and often not the most cost effective way to run their business.  That is why HDD makers continue to develop new technology for platter based storage such as HAMR and shingled magnetic media in an attempt to speed up platter drives as well as increasing the storage density.  Today at The Register you can read about a variety of technologies that will keep the platter alive, from Seagate's cached Enterprise Turbo SSHD, HGST's helium filled drives and the latest predictions on when HAMR and SMR drives could arrive on the market.


"At a briefing session for tech journos yesterday, Seagate dropped hints of new solid-state hybrid drives (SSHDs) - which combine a non-volatile NAND cache with spinning platters - and a general session about Shingled Magnetic Recording (SMR) and Heat-Assisted Magnetic Recording (HAMR)."

Here is some more Tech News from around the web:

Tech Talk

Source: The Register

Hopefully you have had chicken pox already, otherwise you might want to skip Shingled HDDs

Subject: General Tech | June 26, 2013 - 12:56 PM |
Tagged: HAMR, western digital, ssd, hdd, Areal Density

Western Digital, along with Seagate, Toshiba, and Hitachi are working on the next step in increasing the storage density of platter based drives while HAMR is still in the works.  They will be adding overlapping tracks to their platters, which they are referring to as shingles (as in the roof, not the pox).  There will be two types implemented, with the first type having the shingling hidden to ensure compatibility with existing applications which might take exception to overlapping data tracks.  Type two will not hide its light under a bushel and will require applications to be aware of the shingling and hopefully take full advantage of the new type of magnetic recording.  According to the presentation that The Register attended we will see shingles in the near future, with HAMR due in 2016.


"Over the coming years the remaining players will be pushing traditional technology to its limits to extend the life of hard disk technology. While the industry is pretty much standardised on perpendicular magnetic recording (PMR) at present, in a couple of years there will be more fundamental hard drive technologies co-existing in the market than there are hard drive vendors."

Here is some more Tech News from around the web:

Tech Talk

Source: The Register

Seagate Achieves 1 Terabit Per Square Inch Storage Density

Subject: Storage | March 20, 2012 - 01:27 PM |
Tagged: storage, Seagate, hard drives, HAMR, density, 1 Tb/in^2

In April 2006 Seagate began shipping the first 3.5" desktop hard drive using Perpendicular Magnetic Recording (PMR) technology and since then PMR has become essential in allowing all of the hard drive manufacturers to create the 2 TB+ drives available today. As we approach the limits of what drive manufacturers are able to do using PMR alone; however, they are starting to look at additional technologies to boost the storage density. One such technology on the horizon is Heat Assisted Magnetic Recording, or HAMR. According to a recent press release, Seagate is not only experimenting with HAMR but is the first drive manufacturer to use HAMR to reach 1 Terabit per square in of areal density.

HAMR works by using a laser to heat up the storage medium before the compounds used to store data have their orientation aligned by the write heads of the drive. As bits get smaller and smaller, traditional magnetic recording methods are not strong enough to permanently change the magnetic orientation of the bits, which means that there is an inherent, if theoretical, minimum bit size and corresponding maximum storage density possible with current Perpendicular Magnetic Recording. HAMR further allows drive makers to get around that limitation by heating the physical bits to the point that traditional magnetic write heads can change the orientation.


Via Bit-Tech.  The laser heats up the platter before being written to.

The current 1 Terabit per square inch achieved using HAMR is also the theoretical maximum storage density for PMR alone (as mentioned above), which is promising as it implies HAMR still has a lot of working room to improve and has matched the maximum proposed for PMR.

Seagate expects to use HAMR to produce 60 TB+ 3.5" and 20 TB+ 2.5" hard drives within the next ten years. To put this areal density in perspective, current 3 TB desktop drives feature approximately 620 Gigabits per square inch while current 750 GB laptop (2.5") drives feature about 500 Gigabits per square inch.  Interestingly, when comparing the 1 Tb/in^2 mechanical drive density to flash (ie SSD) storage at equivalent densities, it works out such that a single bit equals 1nm of flash storage!

Unfortunately, we won't be seeing 60 TB drives any time soon. Rather, Seagate expects 6 TB desktop drives and 2 TB laptop drives to be the most immediate benefits of the heat assisted recording technology. Still, as my 2 TB drive is filling up more quickly than I ever imagined (thanks to working with HD video and making regular backups of data), I welcome as much increased storage as I can get!

Source: Seagate