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


View All Comments

  • ddrіver - Thursday, December 21, 2017 - link

    @Arnulf, Europe is a civilized land. Reply
  • sonny73n - Wednesday, December 20, 2017 - link

    You remind me of the path I crossed with Samsung customer service about my 840 Evo (2 months old then).

    Dear valued customer,
    Please contact your seller (Newegg)....
    We acknowledged the issue. Please wait for firmware update....

    The worst of all is that all their customer service reps don't know shit but they insisted to guide me, a veteran in IT field, how to install an SSD in my laptop. After firmware update, BSOD still happened but less frequent. Best thing I did was throwing that sucker in the trash.

    Forget Shamesung and their shameless fanboys. This MX500 is a good deal but I prefer the BX300 because of MLC over TLC.
  • Samus - Wednesday, December 20, 2017 - link

    The BX300 is such an incredibly good drive. I've outfitted 20 office PC's with them since they were introduced, no problems whatsoever. Reply
  • ddrіver - Wednesday, December 20, 2017 - link

    @sonny73n, I'll just repost this here: https://www.usenix.org/conference/fast16/technical...
    Short version: the difference between SLC and MLC is almost indistinguishable. Don't imagine that MLC vs. TLC will be a world of difference either. Not with new drives.
  • Samus - Wednesday, December 20, 2017 - link

    I had one of the worst warranty experiences ever with the 840 EVO years ago. Haven't given Samsung money since. OCZ and Mushkin, and Crucial for that matter, all have advanced RMA options and very smooth exchange processes. Crucial offers data recovery starting at $200.

    Samsung doesn't even return initial emails and they lie through their teeth on the phone, if you can even get ahold of the right person after being in a transfer loop for 30 minutes.
  • Cooe - Wednesday, December 20, 2017 - link

    Recently??? Lol try well over 3 years ago. The 850 EVO's been using Samsung's V-NAND (V = vertical, as in 3D) pretty much since it's inception. In fact, they have used 3 (iirc) different types of V-NAND (differing in layer density) so far through production. You need to get with the program lol. Micron's slapping the EVO upside the head here, and I say that as someone who's bought more EVO's then I can count. Reply
  • lilmoe - Wednesday, December 20, 2017 - link

    They just need to lower their damn price, and they'd still be good to go. Their 850 series is tried and proven, with a much better warranty, which is a significant advantage over newly released SATA models.

    Just cut the 850 Pro's price in half already Samsung.... I don't mind if they even cut the 10 year warranty in half dammit.
  • bill.rookard - Tuesday, December 19, 2017 - link

    Agreed. Performance is pretty decent for a change! And having the 1TB available at the 250$ price point is also pretty aggressive as I'm sure it'll come down a stitch more in the next month or two. Reply
  • Samus - Wednesday, December 20, 2017 - link

    The M550, MX100, MX200 and MX300 have always been decent contenders to Samsung 830, 840, 850 and 860, often priced lower and in the same performance bracket. Support and reliability are excellent. Reply
  • Chaitanya - Tuesday, December 19, 2017 - link

    surprising crucial decided to keep mx line on tlc nand while bx was upgraded to mlc nand. Reply

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