Samsung Introducing Z-NAND Based 800GB Z-SSD For Enterprise HPC
Subject: Storage | January 31, 2018 - 08:39 PM | Tim Verry
Tagged: z-ssd, Z-NAND, Samsung, HPC, enterprise, ai
Samsung will be introducing a new high performance solid state drive using new Z-NAND flash at ISSCC next month. The new Samsung SZ985 Z-SSD is aimed squarely at the high-performance computing (HPC) market for big data number crunching, supercomputing, AI research, and IoT application development. The new drive will come in two capacities at 800GB and 240GB and combines low latency Z-NAND flash with 1.5GB LPDDR4 DRAM cache and an unspecified "high performance" Samsung controller.
The Z-NAND drive is interesting because it represents an extremely fast storage solution that offers up to 10-times cell read performance and 5-times less write latency than 3-bit V-NAND based drives such as Samsung's own PM963 NVMe SSD. The Z-NAND technology represents a middle ground (though closer to Optane than not) between NAND and X Point flash memory without the expense and complexity of 3D XPoint (at least, in theory). The single port 4-lane drive (PCI-E x4) reportedly is able to hit random read performance of 750,000 IOPS and random write performance of 170,000 IOPS. The drive is able to do this with very little latency at around 16µs (microseconds). To put that in perspective, a traditional NVMe SSD can exhibit write latencies of around 90+ microseconds while Optane sits at around half the latency of Z-NAND (~8-10µs). You can find a comparison chart of latency percentiles of various storage technologies here. While the press release did not go into transfer speeds or read latencies, Samsung talked about that late last year when it revealed the drive's existence. The SZ985 Z-SSD maxes out its x4 interface at 3.2 GB/s for both sequential reads and sequential writes. Further, read latencies are rated at between 12µs and 20µs. At the time Allyn noted that the 30 drive writes per day (DWPD) matched that of Intel's P4800X and stated that it was an impressive feat considering Samsung is essentially running its V-NAND flash in a different mode with Z-NAND. Looking at the specs, the Samsung SZ985 Z-SSD has the same 2 million hours MTBF but is actually rated higher for endurance at 42 Petabytes over five years (versus 41 PB). Both drives appear to offer the same 5-year warranty though we may have to wait for the ISSCC announcement for confirmation on that.
It appears that the SZ-985 offers a bit more capacity, higher random read IOPS, and better sequential performance but with slightly more latency and lower random write IOPS than the 3D XPoint based Intel Optane P4800X drive.
In all Samsung has an interesting drive and if they can price it right I can see them selling a ton of these drives to the enterprise market for big data analytics tasks as well as a high-speed drive for researchers. I am looking forward to more information being released about the Z-SSD and its Z-NAND flash technology at the ISSCC (International Solid-State Circuits Conference) in mid-February.