HAMR and MAMR: The Technologies That Will Unlock Hard Drive Capacity This Year

Data management is a constant headache for photographers and videographers. Fortunately, hard drive manufacturers are going to release two new technologies this year geared to increase storage capacity.

With the advent of ultra-high-resolution sensors and raw video cameras at the consumer level, storing our files is becoming a significant problem. Simply put, hard drive capacity doesn’t grow as fast as our media libraries. Cloud storage is also limited by the speed of our internet connections. Uploading TB of images takes times, especially without a fiberoptic connection. Unfortunately, hard drive capacity has been quite stagnant for the past few years, but things are about to change.

HAMR and MAMR: Not a Revolution

Before you get too excited, HAMR and MAMR technologies won’t dramatically increase the current capacities. These technologies are just an evolution, not a radical breakthrough. According to the manufacturers, the first disks should hit the market sometime this year with 16-to-20 TB models, which is not a massive improvement considering that the largest consumer level drives available today can store up to 14 TB. By 2023, Seagate expects to deliver 40 TB+ hard drives.

At the moment, the three leading manufacturers use the same technology that was introduced 10 years ago:  PMR (Perpendicular Magnetic Recording). And PMR itself was an evolution of the previous LMR (Longitudinal Magnetic Recording) storage process. Another development of PMR exists, the SMR. However, the underlying method by which the bits are recorded is the same. Thus, even with the combined benefits of PMR and SMR, we’re approaching the limits with this technology as well. Today’s PMR will eventually run out of steam due to the laws of physics.

Seagate, like Toshiba and Western Digital, is now going to introduce another variation to escape the inability of the current PMR technology to increase the areal density of the disk.

Without being too technical, there are two main techniques to increase hard drive capacity: add more platters inside the hard drive or cram more pieces of data (bits) on a given surface area (disk). Designers used these two avenues in parallel for decades, but the first one (increase the platter density) can’t be pushed much further anymore: the 3.5” disks are already filled with platters and the air inside the core has been replaced by helium, while future designs may be vacuum-sealed to get rid of the last amount of gas resistance. Increasing the data density is the only way left to significantly improve the storage capacity. But as the Chief Technology Officer of Seagate explains: “it sounds almost simple, but the science and engineering expertise required to perfect this technology has been enormous. Increasing the amount of data you can store on a disk requires cramming magnetic regions closer together, which means the grains need to be smaller, so they won’t interfere with each other. The major problem with packing bits so closely together is that if you do that on conventional magnetic media, the bits (and the data they represent) become thermally unstable and may flip.”

Indeed, writing more data on less surface creates a lot of instability, and instability is not something desirable in the business of data storage. The remedy is to use a more stable recording medium, one known as a high coercivity or hardness, to simplify it. But that coercivity has to be overcome to write on the hard drive platter. Said otherwise, past a certain level of miniaturization, you need a “harder” material to keep your data stable, but the toughness of this material prevents the writing operation.

However, if some kind of energy is applied to this high coercivity media during the writing phase, the coercivity is effectively reduced to the point where the recording head can write information on the media tracks. Essentially, MAMR and HAMR are energy-assisted recording techniques used to “soften” the “hard” but stable high coercivity material. The two technologies use different energy approaches to overcome the coercivity of the medium during the writing phase:

• MAMR: Microwave-Assisted Magnetic Recording uses 20-40 GHz frequencies to bombard the disk platter with a circular microwave field, lowering its coercivity and enabling the bit value to be written.
• HAMR: Heat-Assisted Magnetic Recording uses a tiny 200 mW laser beam to heat up the disk platter to 750 °F (400 °C) and permit the writing operation.

Western Digital and Toshiba are pursuing the MAMR (microwave energy assist) technology, while Seagate bets on the HAMR (heat energy assist). But both technologies share a common goal: increase the areal density to produce larger capacity hard drives.

Availability, Capacity, and Performance

Western Digital and Seagate plan to begin volume shipments of their respective technologies sometime this year. Western Digital revealed recently that it has begun to sample pre-mass production models (16 TB) and 18 TB units may follow before the end of 2019. On paper, Seagate announced 40 TB+ drives by 2023, while WD plans to pass the 40 TB threshold in 2025. The first Seagate drives available this year should reach 20 TB of storage if everything goes according to plan.

But the initial models will be dedicated to professional use and will address data center needs first. It is not clear at this time when these new hard drives will hit the consumer market.

Regarding capacity, WD claims MAMR drives will top out at 4 Tb/in^2, whereas Seagate's HAMR is widely projected to top out at 10 Tb/in^2. Beyond that, Seagate expects to pair HAMR with Bit-Patterned Media, thus creating HDMR (Heated Dot Magnetic Recording) to scale up to 100 Tb/in^2. WD could also try something similar with its MAMR technology.

What about performance? Manufacturers indicate that speed will be directly correlated to capacity as higher density platters allow one to increase the transfer speed. Knowing that the latest 12 TB PMR hard drives can reach up to 240 MB/s, a 40 TB drive should be able to transfer data at 350 or 450 MB/s, but this figure is just a rough estimate based on extrapolation. As for latency, it will mainly depend on the rotation speed (5,400 rpm, 7,200 rpm or other). We’ll have to wait for the first reviews to have a precise idea of the performance.

Price, Reliability, and Compatibility

Finally, the cost factor is unknown, and manufacturers are not very talkative at this point. According to Seagate: “although new HAMR components add some cost on a per-head basis, HAMR drives as a whole can deliver a reduced cost-per-TB compared to PMR drives because of the sheer increase in total capacity per disk.” Initially, the MAMR and HAMR technology shouldn’t come cheap, but the price should decrease as data centers start ordering millions of units. However, I wouldn’t bet on affordable MAMR, and HAMR drives this year.

As usual, each side claims to offer a superior solution while downplaying the technology of its competitors. WD contends that Seagate’s HAMR increases production costs because of the new material required for the platters. It also expresses doubts about the reliability of lasers, which is one of the critical reasons WD chose MAMR instead of HAMR. But Seagate countered that increased storage density yields a lower cost per TB and dismissed reliability concerns by saying that it has already built and tested more than 40,000 HAMR drives with millions of heads. And contrary to WD's claims, Seagate says HAMR drives are plug and play with existing systems.

Conclusion

HAMR and MAMR are just an evolutionary step of the current technology. Without being a radical breakthrough, they allow one to unlock the current limitation of the PMR recording architecture and open the door to 40 TB+ drives by 2023-2025 according to the vendor’s roadmaps. Most likely, the new hard drives will be paired with other technologies, such as helium, SMR, and TDMR to increase density as the technology matures. But the first models to hit the market this year will be 16 TB to 20 TB drives dedicated for data centers, and the prices  shouldn’t be consumer friendly. Performance, compatibility, and reliability will have to be established once reviewers can get their hands on the first units.