https://arstechnica.com/gadgets/2018/02/samsung-crams-30tb-of-ssd-into-a-single-2-5-inch-drive/

If you need to pack more storage into your enterprise systems, then boy has Samsung got the SSD for you. The new PM1643 boasts a capacity of 30.72TB in a standard 2.5-inch drive.

On the inside, the drive has nine flash controllers driving 32 1TB packages of NAND flash, with each package containing 16 layers of 512Gb 3-bit-per-cell V-NAND. There's also 40GB of DDR4 RAM. The RAM is unusual, too; the 8Gb chips are built using Through Silicon Vias (TSVs), enabling them to be stacked vertically. They're assembled into 10 packages each of 4GB.