PCI-Express 2x 3.0 NVMe 1.3 Interface, M.2 2280 Form Factor, 128GB Total Capacity, NAND Flash, 1.5M hours Mean time between failure (MTBF). The Host Memory Buffer (HMB) feature utilizes the DMA (Direct Memory Access) of PCI Express to allow SSDs to use some of the DRAM on PC system, instead of requiring the SSD to bring its own DRAM.