3D NAND bits surpassed 50 per cent of total NAND Flash bits supplied in 2017's third quarter, and are estimated to reach 85 per cent by the end of 2018,Despite this increase in capacity, price per bit has increased recently. Rakers' sources all predict that prices will resume their decrease shortly. They didn't predict the increase, so some skepticism is in order. They differ about the rate of the decrease:
IDC thinks there will be a $/GB decline of 36 per cent year-on-year 2018. TrendForce (DRAMeXchange) recently forecast that 2018 NAND Flash price declines would be in the 10 to 20 per cent year-on-year range. Western Digital concurs with that from a 3D NAND viewpoint, and has reported having seen 3D NAND price declines in the 15 - 25 per cent per annum range.
He looked at SSD ships related to disk drive ships on a capacity basis, seeing the flash percentage share rising to 19.3 per cent in 2021 from 8.4 per cent this year:So, as I projected, Rakers agrees that in 2021 bulk data will still reside overwhelmingly on hard disk, with flash restricted to premium markets that can justify its higher cost.
Mellor ends on a cautionary note, with which I concur:
It's still not clear if QLC (4bits/cell) flash will actually be an enterprise-class technology. Flash capacity increases beyond that might stall because there is nothing beyond QLC, such as a theoretical PLC (penta level cell - 5bits/cell) technology, or layering beyond 96 x 3D NAND layers might hit a roadblock.