Building high-performance SSDs requires the use of multiple high-performance 3D NAND flash memory devices, which is why the fastest client SSDs usually come in an M.2-2280 form-factor. As devices become smaller many modern PCs require small yet fast storage devices. This week Kioxia introduced its BG5 family of tiny SSDs that bring together an M.2 form-factor, a PCIe 4.0 interface, and decent performance.
Kioxia's BG5-series SSDs carry 256GB, 512GB or 1024GB of the company's 112-layer BiCS5 3D NAND memory with a 1.2 GT/s interface and come in an M.2-2230 form-factor. The drives rely on an unknown NVMe 1.4-compliant controller (most probably from Phison, though we a speculating), though Kioxia probably uses its own firmware to optimize performance and power consumption of its tiny SSDs.
Speaking of performance, Kioxia rates its BG5 drives for up to 3,500 MB/s sequential read and an up to 2,900 MB/s sequential write speed as well as up to 500K random read IOPS and up to 450K random read IOPS.
While these level of performance are somewhat below from what we come to expect from an SSD with a PCIe 4.0 x4 interface, keep in mind that the BG5 cannot physically use many 3D NAND chips, so its potential performance is limited by its form-factor. Performance of Kioxia's BG5 drives is noticeably higher compared to performance of Samsung's tiny PM991/PM991a drives that are rated for up to 3.10 GBps/2.0 GBps sequential read/write speeds.
While Kioxia's BG5 SSDs are the fastest client drives in an M.2-2230 form-factor, they have one caveat. Unlike the company's previous-generation BG-series SSDs, these new drives are not available in BGA form-factor, which prevents their installation into PCs that require even smaller drives.
Kioxia has not disclosed pricing of its BG5 drives, though since these are DRAM-less SSDs, expect them to be relatively cheap to build. Meanwhile, expect Kioxia to demand a premium for the combination of tiny dimensions and high performance. It is noteworthy that for those who do not need tiny dimensions, Kioxia will offer BG7 drives in an M.2-2280 form-factor too.
"Market adoption of DRAM-less SSDs is increasing steadily, thanks to HMB's ability to reduce the overall bill of materials without degrading the data read/write performance of the SSD," noted Neville Ichhaporia, vice president, SSD marketing and product management, Kioxia America, Inc. "The fact that Kioxia realized PCIe 4.0 performance with a DRAM-less architecture is a win for mainstream client applications."