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 power usage seems to have taken a step backward from the Crucial MX300 to the Crucial MX500. Both the active idle and the slumber power state consumption are higher than most mainstream SATA SSDs, but it isn't one of the extreme outliers that has broken power management.

Idle Wake-Up Latency

The idle wake-up time for the Crucial MX500 of about 1ms is higher than many mainstream drives, but is a big improvement over the 3.3ms of the Crucial MX300. The Marvell-based drives from Western Digital/SanDisk seem to offer the best combination of low power consumption and quick wake-ups.

Mixed Read/Write Performance Conclusion
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  • Kristian Vättö - Wednesday, December 20, 2017 - link

    MLC and TLC are different at die level. Once the wafer is produced it's no longer possible to switch from MLC to TLC or vice versa. Sure TLC could be used in pseudo-MLC mode by only programming the lower and middle pages, but that is not the same thing. Reply
  • mode_13h - Wednesday, December 20, 2017 - link

    I'm not saying you're wrong, but please explain how Crucial's Dynamic Write Acceleration gets a significant write performance benefit by doing similar. Reply
  • MajGenRelativity - Tuesday, December 19, 2017 - link

    I'm pleased with this product. Keep up the good work Micron, and keep lowering SSD prices! Reply
  • jjj - Tuesday, December 19, 2017 - link

    A bit suspicious that there are no specs and prices for the 512GB version, hopefully the perf drop won't be too large.
    Other than that, all good here.
    Reply
  • Billy Tallis - Tuesday, December 19, 2017 - link

    Officially, Crucial is only launching the 1TB model today. The other capacities have to wait a little longer for a proper announcement. Reply
  • The Benjamins - Tuesday, December 19, 2017 - link

    They will offically have a 250GB, 500GB, 1TB, 2TB models in 2.5" and up to 1TB in M.2
    http://www.crucial.com/wcsstore/CrucialSAS/pdf/pro...
    Reply
  • witp - Tuesday, December 19, 2017 - link

    Got other capacities prices, unofficialy ofc.
    Excl VAT, incl distributors' margin, for both M.2 and 2.5'' versions, that will be:
    250GB ~74USD
    500GB ~130USD
    1TB ~238USD ; for comparison
    2TB 2.5'' only ~465USD
    Availability here in duckland ;) please don't mistake with Deutchland ;))) for W02/18
    Reply
  • jjj - Tuesday, December 19, 2017 - link

    I supposes my comment wasn't clear enough, wasn't suggesting it's your fault. Anyway, these things are always on purpose and it seems that they don't want to talk about lower capacities at all, they want people to see the MX500 perf as it is today at 1TB. A bit of a red flag but hopefully 512GB will be ok too. Reply
  • Billy Tallis - Tuesday, December 19, 2017 - link

    I'm expecting them to sample at least one of the smaller capacities, if not all of them. I did mention recently that I probably would have given the BX300 an award if they had sent me the 120GB model, because that one is such a clear winner above the sparse competition in that capacity range. Reply
  • jjj - Tuesday, December 19, 2017 - link

    They've been doing a pretty good job with both MX and BX series, good deals usually.
    With the new CEO they should start pushing harder in SSD. I think they had some issues a few months back and maybe that's why this one got delayed but I would expect to see them focusing more on SSD.
    Reply

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