Toshiba announces a breakthrough in the development of hard drives with Microwave Assisted Magnetic Recording (MAMR), in which microwave transmitters in the head increase write performance. Thus, the data density can continue to grow, which should “soon” allow HDDs with capacities of 30 TB and more.
So far, Toshiba has only sold an 18 TB hard drive, the MG09, which relies on an early form of microwave technology in the form of Flux Control MAMR (FC-MAMR). The manufacturer equips existing heads with a simple microwave transmitter that pushes the magnetic particles on the disks in the right direction when writing before the writing head does the rest. The data density increases by around 20 percent compared to conventional recording technology.
Significantly bigger improvements brings the so-called Microwave Assisted Switching-MAMR (MAS-MAMR). Together with the magnetic disc manufacturer Showa Denko KK (SDK) and the read/write head manufacturer TDK Corporation, Toshiba has developed adapted platters and heads: In the heads there is now a double microwave transmitter (“bi-oscillation spin-torque oscillator device [Dual FGL STO]”), which generates more focused microwaves with higher efficiency at the same time. New types of magnetic discs are needed for a real advantage – the partner companies are not yet revealing the details.
Structure of a MAS-MAMR head with dual microwave transmitters.
(Image: Toshiba)
No MAMR at the competition
In the race for the first 30 TB HDDs, competitor Western Digital has now given up further development of microwave technology. Instead, the company continues to use Energy-enhanced Perpendicular Magnetic Recording (ePMR), which is vaguely reminiscent of Toshiba’s FC-MAMR: An electric current is fed into the write head to generate an additional magnetic field there and thus reduce the so-called jitter .
Together with an increase in the number of disks in an HDD housing and flash memory for swapping out user data and metadata (OptiNAND), a capacity of 30 TB should be possible with the existing technology. Seagate, on the other hand, as the third remaining hard drive manufacturer, focuses on temperature-based Heat Assisted Magnetic Recording (HAMR): The magnetic field strength required for writing decreases through selective heating of the magnetic particles.
(mmma)
