Saturday 28 March 2015

3D NAND SSDs at DOORSTEP



We are stuck with using our old magnetic hard drives for decades, new ones like SSDs are too expensive to buy with no sign of relaxation in prices. But now thanks to intel(partnered with micron) and toshiba that came up with brilliant devices based on 3D NAND 
technology for improving the storage in the existing SSDs at low costs. Micron said that the chips with the size of gum sticks can hold data up to 3.5 TB and 2.5” SSD with over 10TB of data. Isn’t that amazing, thanks to 3D NAND i could now download my favorite daily soaps without sacrificing old ones.

Now lets talk about the technology 3D NAND which made this amazing thing possible.
Normally the regular SSD are made from flash storage. Flash uses EEPROM(electrically erasable programable read only memory) which can be either NAND or NOR depending on what logic we have used. 
EEPROM are made using MOSFET transistors.  Generally we prefer NAND however both have their own advantage. EEPROM and has become the dominant memory type wherever a system requires a significant amount of non-volatile, solid-state storage.


NAND flash memory wiring and structure on silicon COURTESY. WIKIPEDIA


3D NAND flash stacks memory cells one on top of another so as to increase the density, the packing may go upto 48 layers or more.






Toshiba announced that it is shipping samples of its 48-layer three-dimensional BiCS (Bit Cost Scalable) stacked cell structure flash. In simpler terms, BiCS is Toshiba's own spin on 3D NAND. The new Toshiba flash comes in 128 Gbit (16 GB) die with 2-bits-per-cell, which is the same number of bits-per-cell compared to standard 2D planar MLC NAND.

The new 3D NAND technology stacks flash cells vertically in 32 layers(intel devices) to achieve 256Gb multilevel cell (MLC) and 384Gb triple-level cell (TLC) die that fit within a standard package. These capacities can enable gum stick-sized SSDs with more than 3.5TB of storage and standard 2.5-inch SSDs with greater than 10TB. Because capacity is achieved by stacking cells vertically, the individual cell dimensions can be considerably larger. This is expected to increase both performance and endurance and make even the TLC designs well-suited for data center storage.
The key product features of this 3D NAND design include:

  • Large Capacities –Three times the capacity of existing 3D technology—up to 48GB of NAND per die—enabling three-fourths of a terabyte to fit in a single fingertip-sized package.
  • Reduced Cost per GB – First-generation 3D NAND is architected to achieve better cost efficiencies than planar NAND.
  • Fast – High read/write bandwidth, I/O speeds and random read performance.
  • Green – New sleep modes enable low-power use by cutting power to inactive NAND die (even when other die in the same package are active), dropping power consumption significantly in standby mode.
  • Smart – Innovative new features improve latency and increase endurance over previous generations, and also make system integration easier.