Flash supply running thin; magneto-RAM proposed as low power alternative

The second half of 2017 is going to see a limited supply of NAND flash memory and OLED screens hit the smartphone market, according to Gartner, leading to shortages and price increases. The squeeze will hit the higher end of the market harder, according to the prediction – the likely impact has already been seen in the launch of AMD’s flagship video card, which was hampered by a shortage of HBM2 (High Bandwidth Memory 2) chips.

“We’ve already seen Huawei’s P10 suffer from a flash memory shortage, and smaller traditional brands, such as HTC, LG, and Sony, are stuck between aggressive Chinese brands and the dominating market shares of Samsung and Apple in the premium smartphone segment,” said Gartner research director Anshul Gupta.

These shortages hit periodically, and can make the difference between profit and loss for a device maker. They drive higher profits for memory makers, of course, but also put pressure on them to increase capacity and investigate new technologies. Samsung, the world leader, will invest $7bn in a Chinese semiconductor plant to meet growing demand for NAND flash memory for mobile devices, the firm announced this week. It will invest the money over three years, in its existing plant in Xi’an.

Samsung had about 41% of the NAND market in the first quarter of this year, while Toshiba, which developed the technology, was in second place with 18%, according to IDC. It will be important for the Korean giant also to be at the forefront of the next innovations in mobile memory – but one interesting development has come not from Korea or Japan, but Russia.

Collectively, the industry has been exploring alternatives to NAND flash for a few years, and while most improvements have been seen in high performance technologies like SSD (solid state disk) storage and video memory (GDDR5, HMB2, 3D NAND), new research from the Moscow Institute of Physics and Technology (MIPT) could find a home inside mobile devices.

Conventional RAM requires a constant voltage to retain its contents, and will lose that cache if the power supply is interrupted. As such, there’s a fixed power consumption to be accommodated in designs – not a problem in data centers, but something that has to be carefully balanced in smartphone designs.

The new approach from MIPT uses a magnetic design that could significantly lower the power requirements for the RAM. The prototypes, developed in partnership with two other Russian institutions, could reduce power draw by a factor of 10,000 – a statistic which should immediately inspire skepticism, until further testing and benchmarks are published.

They key is the use of a piezo-electric material and an opposing magneto-elastic structure inside a memory cell, which the researchers are calling MELRAM. The piezo-electric effect denotes the ability of some materials to create electricity when subjected to mechanical stress, and the magneto-electric effect describes how certain materials become magnetized when moved through electric fields. Essentially, the new design plays these two physical properties against each other.

So layers of piezo-electric and magneto-elastic structures can be designed to recreate the logic gates used in conventional DRAM, using a control voltage to make the memory cell behave as desired. The researchers say that this design is non-volatile, retaining its contents without power, and doesn’t require constant rewrites.

The design exploits the piezo-electric component’s desire to deform when voltage is applied, and then generate voltage when subject to a mechanical force. Because of this (physics is weird), the components can be arranged so that the piezo’s desire to deform along one axis works in opposition to the magneto-elastic’s particular magnetization – and that structure can be magnetized in two different directions. Thus – logic gates.

Currently, the prototype is quite large – around a millimeter square. However, MIPT is confident that it could be miniaturized for use in RAM chips – both for PCs and mobile devices. Getting this down to the nanometer scale required will require a huge investment, but the allure of historically low power consumption will be very tempting.

For a long time, flagship smartphones typically had 1GB of RAM, and 16GB to 32GB of storage. The volatile (loses contents when power supply is interrupted) and non-volatile (retains contents with no power) memory available in flagships has surged in recent years, with most Android flagships over the 3GB RAM mark, and some as high as 8GB, and internal storage now mostly north of 64GB, with 128GB not particularly rare.

As such, the demand for flash memory from smartphone makers has apparently outstripped supply – perhaps because the surge coincides with the growth of SSD usage in PCs and data centers. While technologies like 3D NAND have significantly boosted the storage density of these flash storage chips, increased capacity is useless for a phone if the power consumption is too high.

For the smartphone designers, power consumption is one of the main concerns, and the selection of each component comes down to whether it fits inside a specified power package – rather reminiscent of Apollo 13. A series of compromises will be thrashed out, as the final decisions on RF front-ends, screens, and storage are agreed by the engineering team – before they begin agonizing over how best to fit all those components inside the increasingly thinner form factors.

Returning now to Gartner’s study, the firm’s  figures say Samsung sold 82.5m smartphones in Q2 2017(22.5% market share), with Apple in second place on 44.3m (12.1%). Third-place went to Huawei, on 35.9m units (9.8%), with Oppo in fourth on 26.1m (7.1%), and fifth went to Vivo, on 24.3m (6.6%). The Others section accounted for 153m, some 41.8% of the market. Collectively, total sales stood at 366.2m units in the quarter, up 6.7% compared to Q1 2016, and Android had an 88% share of the market, with iOS on 12%.

“Although demand for utility smartphones remains strong, there is growing demand in emerging markets for 4G smartphones, with more storage, better processors and more advanced cameras. This is translating into higher demand for mid-priced [$150 to $200] smartphones,” said Gupta.

As for regional sales, Gartner says Greater China accounted for 101.5m units on Q2 2017 (27.7% market share), Emerging Asia Pacific bought 78.2m units (21.4%), with North America on 40.4m (11%), Western Europe on 35.8m (9.8%), and Latin America on 32.9m (9%). Others stood at 77.4m (21.1%).

The regional shifts are notable, with China falling to that 27.7% share in Q2 2017 from its 33.3% share in Q2 2016, the year before. The other sectors have pretty much stayed the same, but it seems that Emerging Asia Pacific has snatched up the share that China lost – growing from 17.3% to 21.4%.