Since development of the first hard drive in 1956, which weighted over a thousand kilograms and stored only 5MB of data, storage technology has come a very long way. Modern drives can now store up to 12TB (i.e. 12 million MB) of data and reach up to 150 IOPS (i.e. Input/output Operations Per Second). Over the past few years however, the speed of innovation has slowed down and the rate at which the HDD capacity increases annually has decreased, as we are reaching the maximum possible data density on a single platter. This has led to development of new HDD storage technology such as filling the drives with helium and Perpendicular Magnet Recording (PMR). Nevertheless, even with these innovations, there is simply no more space left on the platters to record more data, and if we wish to keep the 3.5-inch standard used today then we cannot add more platters than we have now.
Despite the aforementioned challenges, technology doesn’t stand still and all the big players in the market are pouring millions of dollars into research and development. None of the following technologies have made it to the consumer market yet.
What is MAMR?
Western Digital has developed a new technology called MAMR (Microwave Assisted Magnetic Recording) which uses microwave radiation to create an electromagnetic field, which in turn lowers the surface resistance of underlying recording media, making writing bits easier. Such a feat was achievable by incorporating a Spin-Torque Oscillator (STO) into the actuator head. MAMR uses 20-40GHz frequencies and the STO bombards a bit area with a circular AC microwave field, allowing the magnetic polarity to be changed as desired.
It is believed that MAMR could lead to 4Tbit/in2 areal densities, which is much more than the 1Tbit/in2 drives available today, eventually leading to drives of capacities as high as 40TB. Nevertheless, the technology is still in the developments stage, thus there is still a long way to go until we reach such capacities. One thing we will see on the market in late 2019 is a 16TB drive from WD that utilizes the MAMR technology and 8 platters.
What is HAMR?
Seagate on the other hand, has been working on HAMR (Heat Assisted Magnetic Recording), which uses laser-powered heating to heat up the platter prior to writing the data, reducing its local magnetic hardness when writing onto it.
Since the platter is heated up before the writing operation occurs, surface degradation might occur, as the temperatures can reach up to 450 C. To combat this issue, Seagate has developed new HAMR drives with platters using glass, allowing for the recording layers to reach higher temperatures without degradation, as well as adding a heat sink and an additional surface layer to control the heat flow.