Toshiba has declared a new generation of BG collection solitary-chip SSDs, with a more recent controller and expanded potential solutions many thanks to the adoption of 3D NAND. The BG collection is Toshiba’s SSD alternative for tablets and ultrabooks that want a smaller form variable than a M.two 2280 module but better general performance and potential than eMMC alternatives.
Toshiba’s BG1 collection was to start with previewed at CES 2015. That to start with generation employs a PCIe two x2 backlink and implements the NVMe 1.1a protocol. The BG1 is readily available in capacities of 128GB and 256GB both as a 16mm by 20mm BGA bundle integrating both equally the SSD controller and NAND flash, or as M.two 2230 detachable modules.
The new BG collection switches from planar MLC NAND to Toshiba’s BiCS 3D TLC NAND. The better for each-die potential makes it possible for for the addition of a 512GB product and makes the bundle marginally thinner. The new SSD controller has been upgraded to operate at PCIe three speeds although continue to with only two lanes. It also now supports NVMe 1.two which includes the optional Host Memory Buffer (HMB) function. We’ve previously viewed HMB carried out by a Marvell controller that also targets very low-conclude NVMe programs.
Toshiba has shared some aspects about how they program to make use of HMB and what its impression on general performance will be. The BG collection employs a DRAM-less SSD controller architecture, but HMB makes it possible for the controller to make use of some of the host system’s DRAM. The BG collection will use host memory to put into action a go through cache of the drive’s NAND mapping tables. This is expected to mostly advantage random entry speeds, wherever a DRAM-less controller would or else have to frequently fetch information from flash in buy to figure out wherever to immediate pending go through and generate functions. On the lookout up some of the NAND mapping data from the buffer in the host’s DRAM—even with the additional latency of fetching it more than PCIe—is a lot quicker than undertaking an extra go through from the flash.
Toshiba has not delivered comprehensive general performance specs for the new BG collection SSDs, but they did provide some benchmark information illustrating the advantage of working with HMB. Applying only 37MB of host DRAM and testing entry velocity to a 16GB part of the SSD, Toshiba measured improvement ranging from 30% for QD1 random reads up to one hundred fifteen% improvement for QD32 random writes.
|Overall performance improvement from enabling HMB|
|Random Read through||30%||sixty five%|
|Random Write||70%||one hundred fifteen%|
Though it seems to be like HMB can do a great deal to ease the worst general performance complications of DRAM-less SSD controllers, the caveat is that it demands assist from the working system’s NVMe driver. HMB is continue to an obscure optional function of NVMe and is not nonetheless supported out of the box by any significant working method, and Toshiba just isn’t at present setting up to provide their possess NVMe motorists for OEMs to bundle with devices working with BG collection SSDs. As a result, it is probable that the to start with generation of devices that undertake the new BG collection SSDs will not be capable to choose comprehensive gain of their abilities.
Carried more than from the previous BG1 collection are assist for TCG Pyrite and the solution of comprehensive TCG Opal encryption assist. The 16mm by 20mm BGA bundle is continue to only 1 gram for the optimum potential, and the optimum thickness is lessened from 1.65mm to 1.60mm. Electricity use could have increased marginally, with the new BG collection SSDs drawing up to two.8W when energetic in contrast to a specification of two.2W usual for the BG1.
The new BG collection SSDs are at present sampling to pick out OEMs, and will be in comprehensive mass production by the conclude of the yr.