14 DAY TRIAL // Most pieces of news about M.2 SSDs have been lackluster, because the drives were wired through SATA III instead of PCI Express. Now, though, there is some incentive to make the fast kind: LSI SandForce SF3700 controller chips.
M.2 SSDs are tiny things, compared to all other SSDs, and if the interface is wired through PCI Express the performance can be of 1.8 GB/s.
Most M.2 drives so far, though, have stuck to SATA III, meaning that they're limited to 550-600 MB/s like 2.5-inch SATA units. In a similar manner, SATA Express devices (12 Gbps) have been sparse.
Even PCI Express card-shaped SSDs have been lying low, though they, at least, have been reaching higher and higher, speed-wise, going above even 2 GB/s.
The new LSI SandForce SF3700 controllers won't allow for quite that much, but it will let SSDs reach 1,800 MB/s read and 1,300 MB/s write. And since PCI Express SSDs sometimes use more than one controller chip, we can probably expect something in the range of 3 GB/s soon.
SHIELD error correction technology will preserve data integrity in case you were worried, as will hard and soft LDPC and DSP technology.
Toshiba,Micron and SK Hynis should all launch new SSDs soon, made from 16nm or 19nm MLC NAND flash (128 Gb).