Micron today announced a new SSD that uses its densest process to date and has a chip that can program the memory to act as high performance SLC or high-capacity MLC flash.
The M600 SSD is a client-class SSD that uses Micron's new 16 nanometer (nm) lithography with 128Gb NAND density.
Because of the greater density (Micron previously used 20nm process lithography), the company was able to drop the cost per gigabyte to as little as 45 cents. The ability to dynamically program the flash also reduces power use and improves write performance as much as 2.8 times over models without the feature, according to Jon Tanguy, Micron's senior technical marketing engineer.
The M600 flash drive draws less than 2 milliwatts of power in sleep mode and averages 150mW during active use, according to Tanguy.
The M600 has a sequential read/write rate of 560 MBps and 510MBps, respectively. The SSD has a random read/write rate of up to 100,000 I/Os per second (IOPS) and 88,000 IOPS, respectively.
The SSD is based on an eight-channel Marvell controller that comes with government-grade hardware encryption using the 256-bit AES protocol.
The M600 is being marketed to manufacturers of corporate notebooks and ultra-thin netbooks, workstations and desktop PCs.
The M600 comes in three form factors, a 2.5-in. SSD, an mSATA card and an M.2 memory stick. The mSATA and M.2 form factors come in capacities of 128GB ($80), 256GB ($140) and 512GB $260). The 2.5-in. SSD (7mm height) comes in all the latter capacities and a 1TB ($450) version. The pricing also drops as the quantity of drives ordered increases, the company said.
While Micron's new client drive is not the cheapest on the market, its sticker price resides right along side consumer-class products.
For example, SanDisk's recently released Ultra II SSD sells for about 44 cents per gigabyte. The Ultra II SSD uses triple-level cell (TLC) NAND flash, meaning it stores three bits of data per NAND flash cell - the densest industry specification to date. As more bits are stored in cells, however, the potential for data errors increases, which requires companies to create more sophisticated error correction code (ECC).
Instead of packing more bits in cells or overprovisioning its SSD with flash capacity, Micron reduced the size of its process technology and added what it calls "Dynamic Write Acceleration," a special firmware that changes flash cells from single-level cell (highest performance) to multi-level cell (greater capacity) technology.
"So you can swap back and forth dynamically in order to deliver a pool of SLC or MLC capacity," Tanguy said. "Any new data programming is performed in SLC mode for really high performance."
The new firmware allows Micron to create a dynamic pool of cache without the need to overprovision. "We think doing this gives us a good method to address client loads that tend to be bursty in nature as opposed to enterprise data center write workloads that tend to be sustained," Tanguy said.
However, changing the NAND flash from SLC to MLC and back again also increases write amplification - or the amount of data that must be erased and rewritten. Increasing write amplification more quickly wears out the usable lifespan of NAND flash.
Tanguy said the additional write amplification introduced with the new "dynamic write acceleration" firmware is "manageable."
To deal with the added write amplification, Tanguy said Micron increased the TRIM command set, meaning blocks of data no longer required can be erased and freed up more often for use instead of needing to be erased and re-written elsewhere in the SSD.
The combination of TRIM and dynamic write acceleration has allowed Micron to increase the overall endurance of its drives - the greater the capacity of the drive, the greater the endurance.
Micron's client-grade SSD predecessor could sustain about 72TB of total write over its lifetime, meaning 72TB worth of writes could be written to the drive before it began to fail.
The M600 series increases that by more than four-fold on its highest capacity model. The 128GB SSD can now sustain 100TB, the 256GB sustains 200TB, the 512GB sustains 300TB and the 1TB 2.5-in. SSD can sustain 400TB of writes, the company said.