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.

Active Idle Power Consumption (No LPM)Idle Power Consumption

Idle Wake-Up Latency

The Optane SSD 800p has a bit of an unusual suite of power management capabilities. Previous Optane products have not implemented any low-power sleep states, giving them quite high idle power consumption but entirely avoiding the problem of latency waking up from a sleep state. The 800p implements a single low-power sleep state, while most NVMe SSDs that have multiple power states have at least two or three idle states with progressively lower power consumption in exchange for higher latency to enter or leave the sleep state. On the other hand, the 800p has three tiers of active power levels, so devices with strict power or thermal limits can constrain the 800p when properly configured.

Unfortunately, our usual idle power testing method didn't work with the 800p, leading it to show only a modest reduction in power rather than a reduction of multiple orders of magnitude. This may be related to the fact that the Optane SSD 800p indicates that it may take over a full second to enter its idle state. This is an unusually high entry latency, and something in our system configuration is likely preventing the 800p from fully transitioning to idle. We will continue to investigate this issue. However, based on the specifications alone, it looks like the 800p could benefit from an intermediate idle state that can be accessed more quickly.

(I should mention here that the last Intel consumer SSD we reviewed, the 760p, also initially showed poor power management on our test. We were eventually able to track this down to an artifact of our test procedure, and determined that the 760p's power management was unlikely to malfunction during real-world usage. The 760p now ranks as the NVMe SSD with the lowest idle power we've measured.)

Mixed Read/Write Performance Conclusion
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  • eddman - Monday, March 12, 2018 - link

    90? It is stated as 20nm in that table up there. Reply
  • Nottheface - Monday, March 12, 2018 - link

    I was told these are not related in a previous article's posts: https://www.anandtech.com/comments/12136/the-intel... Reply
  • Ewitte12 - Monday, April 30, 2018 - link

    They had difficulty keeping the enterprise drives in stock.

    The 2X quote was for RAM. low queue depth obliterates NAND. Most other speeds are on par with NAND (with sustained a bit behind) but this is direct access to the storage. Most NAND drives have sophisticated RAM caching it can be writing way after the bar disappears off your screen.

    The biggest issue with pricing. Optane has high early adopter fees (which come with a few extra bugs usually). Also anything under the 900p is kinda pointless. 3.0x2 and low capacities??? Not worth it.
    Reply
  • Gothmoth - Friday, March 9, 2018 - link

    intel hyped this like crazy and after reading the paper i was hyped too.

    but this seems like just another way for intel to push it´s stock market value with redicolous claims.
    Reply
  • hescominsoon - Friday, March 9, 2018 - link

    Semiaccurate had 3d x-point pegged from the beginning:

    https://www.semiaccurate.com/?s=point
    Reply
  • Ashinjuka - Saturday, March 10, 2018 - link

    Optanic. Reply
  • DanNeely - Thursday, March 8, 2018 - link

    Could we see results from Optane as cache + budget SSD and Optane as cache + high end SSD?

    I'm not sure it'd be worthwhile with a fast SSD since it only beats them in a subset of benches, but it looks capable of giving a decent boost to budget flash. Cost effectiveness vs just buying better flash'd be the harder question.
    Reply
  • iter - Thursday, March 8, 2018 - link

    Cache only makes sense for a HDD. It would make no difference combining it with an SSD. Not in terms of real world application performance anyway.

    Spending on 118 gb of optane is pointless when you can get a decent 512 gb ssd for the same money. Over 200% higher the capacity at 99% of the performance. It is a no brainer. Intel will have to resort to bribing OEMs once again if they are to score any design wins.
    Reply
  • patrickjp93 - Saturday, March 10, 2018 - link

    Uh, think again on big data where the indices for the databases you're running are way too big to fit in memory. AWS is just one cloud provider making extensive use of Optane, especially in DynamoDB, RDS, Memcached, and Lambda where multi-tenant container environments definitely benefit in rapid spinup thanks to the much lower latency 3DXP. Reply
  • Billy Tallis - Thursday, March 8, 2018 - link

    All of our usual SSD tests are for the drive acting as a secondary drive, but Intel's Optane-specific cache software only supports the boot volume, so it's rather awkward to test. Reply

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