Toshiba today unveiled the XG 5 series performance-segment SSDs in the M.2-2280 form-factor. These drives take advantage of the PCI-Express 3.0 x4 interface, and the NVMe 1.2 protocol. At the heart of these drives is Toshiba's 64-layer BiCS Flash (3D TLC NAND flash) memory. Available in capacities of 256 GB, 512 GB, and 1 TB, the drive offers sequential transfer speeds of up to 3,000 MB/s reads, with up to 2,100 MB/s writes. The drive features an SLC-cache feature, in which the drive treats a small portion of the TLC NAND flash as SLC NAND, by storing just 1 bit per cell, hot data is juggled in and out of this portion. The drives will go on sale in the first week of June.