SAS 24G is not new
In the new PM1653, the SAS 4 interface again doubles the performance compared to the previous model, the PM1643 with SAS 12G. The SAS 24G is not new, but is still rather rarely used. SAS-4 with 22.5 Gbit/s symbol rate or 2,400 MB/s net throughput was already available in 2017. Published then only in 2020 by Kioxia was a server SSD with SAS 24G, which was introduced in the PM6 series.
Competition for Kioxia PM6
With the PM1653, Samsung now wants to follow suit and brings out a competitor to the Kioxia PM6. Samsung’s enterprise SSD is also offered with up to 30.72 TB in a 2.5-inch form factor. The dual-port SSD offers a maximum data transfer rate of more than 4,000 MB/s read. Samsung specifies 4,300 MB/s for sequential reading and 3,800 MB/s for sequential writing. Thus, the SSD is almost twice as fast as the PM1643, which achieves 2,100 MB/s read and 2,000 MB/s write. Furthermore, the IOPS in random read could also be doubled to a maximum of 800,000. Depending on the model, the PM1653 achieves 135,000 or 270,000 IOPS in write mode.
Comparing the PM1653 with Samsung’s PM1733 (PCIe 4.0 SSD), the enterprise SSD scores rather poorly. The form factor is the same here, but the U.2 port (PCIe 4.0 x4) achieves up to 7,000 MB/s read and 3,800 MB/s write and more than one million IOPS.
With the dual ports of the PM1653, the reliability of the entire system is ensured. With continuous service checks, if one port fails, the other is able to take over immediately, maintaining stability. This gives business-critical applications in particular the stability they need.
For NAND flash memory, the PM1653 uses a V-NAND V6 with 128-layer architecture. To protect against data loss in the event of a power failure, the SSD has Power-Loss Protection on board. The storage capacities will range from 800 GB up to 30.32 TB. More technical details have not yet been announced by the manufacturer.
Availability and pricing
The new PM1653 will first be delivered as a test sample to “selected customers” and is then expected to go into mass production in the second half of 2021. As usual, prices are not known, but will probably be around 250 euros for the 800 GB variant and 2,800 euros for a capacity of 15.36 TB.