Power Management

Real-world client storage workloads leave SSDs idle most of the time, so the active power measurements presented earlier in this review only account for a small part of what determines a drive's suitability for battery-powered use. Especially under light use, the power efficiency of a SSD is determined mostly be how well it can save power when idle.

SATA SSDs are tested with SATA link power management disabled to measure their active idle power draw, and with it enabled for the deeper idle power consumption score and the idle wake-up latency test. Our testbed, like any ordinary desktop system, cannot trigger the deepest DevSleep idle state.

Idle power management for NVMe SSDs is far more complicated than for SATA SSDs. NVMe SSDs can support several different idle power states, and through the Autonomous Power State Transition (APST) feature the operating system can set a drive's policy for when to drop down to a lower power state. There is typically a tradeoff in that lower-power states take longer to enter and wake up from, so the choice about what power states to use may differ for desktop and notebooks.

We report two idle power measurements. Active idle is representative of a typical desktop, where none of the advanced PCIe link or NVMe power saving features are enabled and the drive is immediately ready to process new commands. The idle power consumption metric is measured with PCIe Active State Power Management L1.2 state enabled and NVMe APST enabled (when supported).

Active Idle Power Consumption (No LPM)Idle Power Consumption

(idle power)

Idle Wake-Up Latency

(idle wake-up)

Mixed Read/Write Performance Conclusion
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  • ddriver - Friday, December 15, 2017 - link

    Which is MLC...

    Samsung realized nobody is catching up in the nand market and decided to push consumer, high end and mainstream enterprise a notch down to TLC.

    So now that MLC is only a "high end enterprise" thing in their portfolio, they decided to pimp it up with a new moniker - z-nand. Alas, it is just good old MLC with a barely incremental controller. And claim that it has anything to do with SLC performance - which it does as much as an a race horse harness makes an old donkey faster.

    They REALLY aren't trying.
  • mapesdhs - Monday, December 18, 2017 - link

    Do you have a link to Intel's original PR articlea about this tech? Other people keep saying you're wrong, but if there is indeed a piece of Intel PR that at least implied an initial launch would provide the sort of speed gains you mention, then you absolutely have a point.
  • jospoortvliet - Thursday, December 21, 2017 - link

    I have no link, but as pointed out below, there is a fight with a strawman going on here. Intel certainly talked about 1000x improvement in latency of flash vs Optane - at that point they are talking about time it takes for a single flash cell vs an Optane cell. As Flash can only write to a block or more, it is far far slower, optane can address a single cell directly. And sure, that might very well be 1000x faster in theory - and even already in this very first Optane SSD.

    But, just like if you make one component (eg a piston) in a car engine 1000x faster the entire car won't drive 1000x faster - the other components also contribute to speed, as do external factors like, you know, wind, asphalt... So the car gets 10% faster as a whole. You see the same here: even if that one part is 1000x faster, flash controllers use a ram cache and splitting data over a dozen channels to overcome the inherent limitation of flash while the NVME protocol and PCIExpress puts limits at latency improvements, so the end result is that the Optane PCIE devices are occasionally >10x faster than SSD's but generally a factor 3-5.

    Of course, if you put them in a DDR4 slot, they'll be unleashed a bit more and would beat a DDR4 SSD solution probably by a factor 30-50 in most cases with peaks of 100x. Still not 1000 and it'll never be...

    So, in short, even if Intel is 100% correct and an individual cell responds 1000x faster, its response has to be mediated by the controller, go over a data bus etc etc. so you'll never measure it like that.
  • jospoortvliet - Thursday, December 21, 2017 - link

    And of course Intel just screams '1000x faster response time' without very clearly identifying they're talking about a theoretical maximum. Well, it is marketing. You take the best looking numbers that are defensible and use them.
  • eddman - Thursday, December 21, 2017 - link

    No, intel claimed it for 3D xpoint, NOT optane. Xpoint is the name of the tech, optane is the storage devices based on the tech.
  • Kidster3001 - Wednesday, January 3, 2018 - link

    Intel never claimed Optane to be 1000x faster than anything. The 1000x faster was in reference to 3D-XPoint. XPoint = the memory cells; Optane = the SSD product line. Two completely different things.
  • ddrіver - Saturday, December 16, 2017 - link

    I'm not myself when I drink.
  • farazgomot - Saturday, December 16, 2017 - link

    I fully agree, why almost everybody is caustic to ddriver when he correctly is critic to only the marketing hype , not that the product is in any way bad ( except for the high price/ capacity)
  • lmcd - Saturday, December 16, 2017 - link

    He's arguing semantics when ridiculous performance claims are an industry norm. He's argued those semantics for 5 straight articles, and arguing with literally every comment he can find this very point. It's in the ballpark of 100 belligerent comments on 5 articles, which frankly is far closer to "caustic" than our collective treatment. It's fine if he states his opinion, but we're tired of being screamed at.
  • Reflex - Saturday, December 16, 2017 - link

    The problem with ddriver is that he is arguing against a strawman that was built up in his own mind. Optane was never promised to produce products that could deliver 1000x performance boosts in the first generation. PCM is itself as much as 1000x faster than traditional NAND for many operations while being orders of magnitude more durable.

    However the fact that you are using Optane/PCM does not in some way fix the fact that controllers aren't capable of that kind of performance yet, that PCIe bandwidth is way behind that level, that system memory, chipsets and CPU's couldn't keep up with that, that the software stack is not optimized for that, etc etc.

    Intel delivered, mostly on time and for a cheaper price than is typical for a first gen of a new technology. Since they have previously stated what the performance capabilities of Optane/PCM are, the focus now will be on other aspects of the platform in order to enable that capability. This removes a major performance roadblock as they move towards an optical bus and optical chips, and ensures that system storage is not the long pole.

    I'm fairly excited, its been ten years since any major change in storage has occurred and now it is finally here. And its reasonably priced for what it delivers from the get go.

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