Intel's Optane SSDs and the 3D Xpoint memory they're based on offer impressive latency and quality-of-service consistency. Samsung is now ready to fire back with its own high-end SSDs based on a technology that it calls Z-NAND. The new drives are called Z-SSDs, and judging from what Samsung says, they're quite credible competitors for Intel and Micron's technology.
The Z-SSDs that Samsung is announcing today are members of the SZ985 series, and they'll come in 800 GB and 240 GB capacities. Samsung only lists specifications for the 800 GB model, so keep that in mind as you read on. The drives use Z-NAND in combination with 1.5 GB of LPDDR4 memory and "a high performance controller" that Samsung offers no other details about. The company does say that Z-NAND offers "10 times higher cell read performance than 3-bit V-NAND."
Intel's Optane SSD DC P4800X offers impressive performance, especially with regards to latency and especially consistent latencies under heavy load. Intel claims that the P4800X can respond to I/O requests in under 10 microseconds. Samsung says its new drive comes close to hitting that mark with as little as 12 μs latency on reads and 16 μs on writes. The SZ985 has some advantages, too: Samsung puts it down for 3.2 GB/s on both sequential reads and writes, figures superior to the 2.5 GB/s for reads and 2.2 GB/s writes of Intel's DC P4800X. The Samsung drive also will supposedly do up to 750K IOPS in random reads. Samsung doesn't talk about the queue depths behind those numbers, however, and low queue depths are another place where Optane drives shine. NAND SSDs typically need much higher QDs to exhibit maximum performance, but we're not certain how that logic applies to Z-NAND yet.
The Z-SSDs' random write performance is a bit less impressive at 170K IOPS, falling well short of the nearly-symmetrical 500K IOPS figure of Intel's product. The durability of Samsung's product is through the ceiling, though. The company claims its new drives will withstand 30 full writes per day for five years—a total of about 42 petabytes of writes, on par with the 41-PBW rating of the DC P4800X.
Samsung actually announced Z-NAND and the Z-SSDs back in 2016, and was calling the drives "launched" in August of last year. That timeline obviously slipped, and the company isn't shipping all of the capacities it originally promised. Still, better late than never. You can read the product brief for the SZ985s here. If you're eager to see one in person, Samsung will be showing the Z-SSDs at ISSCC 2018 in San Francisco starting February 11.