Conclusion

The Samsung 983 ZET and related Z-NAND drives are meant to deliver higher performance than any other flash-based SSD currently available. Thanks to the innate benefits of SLC NAND and Samsung's further efforts to optimize the resulting Z-NAND for reads and writes, the company has put together what is undoubtedly some of the best-performing NAND we've ever seen. But is this enough to give the company and its Z-NAND-based drives and edge over the competition, both flash and otherwise?

Compared to other flash-based enterprise SSDs, the 983 ZET certainly provides better performance than is otherwise possible for drives of such low capacity. The random read performance is unmatched by even the largest and most powerful TLC-based drives we've tested so far. But Z-NAND offers little advantage for sustained write performance, so the small capacity and low overprovisioning ratio of the 983 ZET leaves it at a disadvantage compared to similarly priced TLC drives. However, even when its throughput is unimpressive, the 983 ZET never fails to provide very low latency and excellent QoS that no other current flash-based SSD can beat.

While the 983 ZET is an excellent performer by the standards of flash-based SSDs, those aren't its primary competition. Rather, Intel's Optane SSDs are, and In almost every way the 983 ZET falls short of the Optane drives that motivated Samsung to develop Z-NAND. Samsung wasn't really aiming quite that high with their Z-SSDs, so the more important question is whether the 983 ZET comes close enough, given that it is about 35% cheaper per GB based on current pricing online. (Volume pricing may differ significantly, but is not generally public information.)

Whether the 983 ZET is worthwhile or preferable to the Optane SSD DC P4800X is highly dependent on the workload. The Optane SSD provides great performance on almost any workload regardless of the mix of reads and writes, and latency is low and consistent. Comparatively, the Samsung 983 ZET's strengths are very narrowly concentrated: it is basically all about the random read performance, and its maximum throughput is significantly higher than the Optane SSD while still being attainable with reasonably low latency and queue depths. Otherwise there are some massive TLC-based enterprise SSDs that also get close to 1M random read IOPS, but only with extremely high queue depths. The 983 ZET also offers better sequential read throughput than the Optane SSD, but there are far cheaper drives that can do the same.

The biggest problem for the 983 ZET is that its excellent performance only holds up for extremely read-intensive workloads; it doesn't take many writes to drag performance down. This is because Z-NAND is still afflicted by the need for wear leveling and complicated flash management with very slow block erase operations. On sustained write workloads, those background processes become the bottleneck. Intel's 3D XPoint memory allows in-place modification of data in fine-grained chunks, which is why its write performance doesn't fall off a cliff when the drive fills up. It would be interesting to see how much this performance gap between Z-NAND and 3D XPoint can be alleviated by overprovisioning, but there's not a lot of room to add to the BOM of the 983 ZET before it ends up matching the price of the Optane SSD DC P4800X.

Power efficiency is usually not a big concern for use cases that call for a premium SSD like the 983 ZET or an Optane SSD, but the Samsung 983 ZET does well here, thanks in part to the Samsung Phoenix controller it shares with Samsung's consumer product line. The Phoenix controller is designed to work within the constraints of a M.2 SSD in a battery-powered system, so it uses far less power than most high-end enterprise-only SSD controllers. The 983 ZET does consistently draw a bit more power than the TLC-based 983 DCT, but both still have competitive power efficiency in general. On the random read workloads where the 983 ZET offers unsurpassed performance, it also has a big power efficiency advantage over everything else, including the Intel Optane SSDs.

In the long run, Samsung is still working to develop their own alternative memory technologies; they've publicly disclosed that they are researching Spin-Torque Magnetoresistive RAM (ST-MRAM) and phase change memories, so Z-NAND may end up being more of an interim technology to fill a gap that will hopefully be better served by a new memory in a few years. But in the meantime, Z-NAND does have a niche to compete in, even if it's a bit narrower than the range of use cases that Intel's Optane SSDs are suitable for.

Mixed I/O & NoSQL Database Performance
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  • Samus - Tuesday, February 19, 2019 - link

    You can buy SIX 480GB Enterprise-class eMLC drives with around half the write endurance and slightly less performance for the same price. That means you could double up TWO drives 3x in varying configurations or RAID to have similar endurance.

    The margins on this thing must be ridiculous. We thought X-point prices were out of this world but this is out of this galaxy. It would be competitive at HALF the price, but the fact is X-point is better and somehow, shockingly, its actually cheaper!?
    Reply
  • PeachNCream - Tuesday, February 19, 2019 - link

    Why would prices need to be in this galaxy when we're talking about a Samsung Galaxy instead?

    Sorry, I couldn't resist...I'll leave now.
    Reply
  • eastcoast_pete - Tuesday, February 19, 2019 - link

    Definitely NOT a consumer drive.
    @Billy Regarding the Optane drive performance: any information or experience with DIMM format Optane? I believe Intel launched DDR4 slot format compatible Optane modules. How much faster are they than the PCI-E drives?
    Reply
  • ksec - Tuesday, February 19, 2019 - link

    I don't think any consumer would be interested in these. Would love ServeTheHome doing some DB testing with it. Looking at the price and performance I think that is going to Win a lot of business from Optane. NAND price are dropping as well, so Samsung would have lots of capacity for Shipment. Reply
  • MamiyaOtaru - Tuesday, February 19, 2019 - link

    where's ddriver? He was constantly banging on about how terrible "hypetane" is (and how clever he was for coming up with that nickname) and how SLC would kick its ass

    ""no other alternative nonvolatile memory technology is close to being ready to challenge 3D XPoint"

    Except for SLC, which was so good it was immediately abandoned once inferior and more profit friendly NAND implementations were available.

    A SLC based product coupled with MRAM cache will easily humiliate hypetane in its few strong aspects."
    https://www.anandtech.com/show/11953/the-intel-opt...

    I am still disappointed by optane, and now I'm disappointed by znand (performance and price). Wish we had some non-volatile memory that was affordable and not trending towards more and more fragility (QLC)
    Reply
  • JoeyJoJo123 - Tuesday, February 19, 2019 - link

    Looks like I'm not the only one that remembers the absurdity in trying to bring back SLC for common end user machines.

    The price/GB says it all. It's for enterprise or extreme enthusiasts only, and that's fine, because these deep wallet customers push the industry forward. It's just at the end of the day, if you need the best, you need to pay to get the best. Whining about MLC/TLC/QLC/Optane etc doesn't make the end-user products better.
    Reply
  • WithoutWeakness - Tuesday, February 19, 2019 - link

    Hahaha I was hoping someone else would remember the absurdity of that comment thread. I thought of it as soon as I read that this drive was running SLC. Shame ddriver hasn't shown up here to provide his valuable insight and tell us what the engineers at Samsung did wrong and what they should have changed in order to beat Optane in mixed workloads. Reply
  • PaoDeTech - Tuesday, February 19, 2019 - link

    Ovonic is the word. Reply
  • Fujikoma - Tuesday, February 19, 2019 - link

    "The tradeoff is that they offer less density per cell – one-half or one-third".

    Should be one-quarter, not one-third... power of 2.
    Reply
  • Billy Tallis - Tuesday, February 19, 2019 - link

    TLC is three bits per cell, which is three times the density of SLC. The powers of two show up when you count the number of possible voltage levels that a cell may be programmed to, but that doesn't directly affect density, just endurance and the required amount of error correction. Reply

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