The various varieties of 3D NAND are quite a bit of a hot topic lately. Every NAND maker is set on stacking layers ever higher, and last May Toshiba spoke of 64-layer BiCS flash inching closer to production. That memory is now in an actual shipping product: Sandisk Ultra 3D solid-state drives.
We touched on these drives a while ago, so here's a brief recap: they come in capacities up to 2TB, in a 2.5" form factor with a SATA interface. The sequential I/O figures aren't going to knock the socks off NVMe drives, but they're pretty respectable for SATA offerings at 560 MB/s for reads and 530 MB/s for writes. The drives are pretty nimble in random I/O, too: 95K read IOPS and 81K write IOPS. The 250GB model has marginally slower performance figures, though not by much. Endurance ratings go as follows:
|250 GB||500 GB||1TB||2TB|
|100 TBW||200 TBW||400 TBW||500 TBW|
The tech specs are all solid, but the appeal for these drives is the pricing, particularly for the bigger models. The 250GB model goes for $100, and the 500GB version costs $165. The large 1TB drive will set you back $285, and the larger 2TB unit rings in at $549. Those are pretty aggressive prices considering these drives' performance at the top of the SATA drive rung. Sandisk offers three-year warranty coverage on the Ultra 3D SSDs.