Power Management Features

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.

For many NVMe SSDs, the closely related matter of thermal management can also be important. M.2 SSDs can concentrate a lot of power in a very small space. They may also be used in locations with high ambient temperatures and poor cooling, such as tucked under a GPU on a desktop motherboard, or in a poorly-ventilated notebook.

Crucial P1
NVMe Power and Thermal Management Features
Controller Silicon Motion SM2263
Firmware P3CR010
NVMe
Version
Feature Status
1.0 Number of operational (active) power states 3
1.1 Number of non-operational (idle) power states 2
Autonomous Power State Transition (APST) Supported
1.2 Warning Temperature 70 °C
Critical Temperature 80 °C
1.3 Host Controlled Thermal Management Supported
 Non-Operational Power State Permissive Mode Not Supported

The Crucial P1 includes a fairly typical feature set for a consumer NVMe SSD, with two idle states that should both be quick to get in and out of. The three different active power states probably make little difference in practice, because even in our synthetic benchmarks the P1 seldom draws more than 3-4W.

Crucial P1
NVMe Power States
Controller Silicon Motion SM2263
Firmware P3CR010
Power
State
Maximum
Power
Active/Idle Entry
Latency
Exit
Latency
PS 0 9 W Active - -
PS 1 4.6 W Active - -
PS 2 3.8 W Active - -
PS 3 50 mW Idle 1 ms 1 ms
PS 4 4 mW Idle 6 ms 8 ms

Note that the above tables reflect only the information provided by the drive to the OS. The power and latency numbers are often very conservative estimates, but they are what the OS uses to determine which idle states to use and how long to wait before dropping to a deeper idle state.

Idle Power Measurement

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 if supported.

Active Idle Power Consumption (No LPM)Idle Power Consumption

The idle power consumption numbers from the Crucial P1 match the pattern seen with other recent Silicon Motion platforms. The active idle draw is a bit higher for the P1 than the 660p due to the latter having less DRAM, but both do very well when put to sleep.

Idle Wake-Up Latency

The wake-up latency of over 73ms for the Crucial P1 is fairly high, and definitely much worse than what the drive advertises to the operating system. This could lead to some responsiveness problems if the OS is misled into choosing an overly-aggressive power management strategy.

Mixed Read/Write Performance Conclusion
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  • Lolimaster - Friday, November 9, 2018 - link

    With worse of everything how is it going to be "faster", do any TLC SSD beat the Samsung MLC ones? No.
  • Valantar - Thursday, November 8, 2018 - link

    What's the point of increasing performance when current top-level performance is already so high as to be nigh unnoticeable? The real-world difference between a good mid-range NVMe drive and a high end one are barely measurable in actual real-world workloads, let alone noticeable. Sure, improving random perf would be worthwhile, but that's not happening with flash any time soon. Increasing capacity per dollar while maintaining satisfactory performance is clearly a worthy goal. The only issue is that this, as with most drives at launch, is overpriced. It'll come down, though.
  • JoeyJoJo123 - Thursday, November 8, 2018 - link

    ^ This.

    For typical end users, even NVMe over SATA3 SSDs don't provide a noticeable difference in overall system performance. Moving to an SSD over an HDD for your OS install was a different story and a noticeable upgrade, but that kind of noticeable upgrade just isn't going to happen anymore.

    Typical end users aren't writing/reading so much off the drive that QLC presents a noticeable downgrade over TLC, or even MLC storage. Yes, right now QLC isn't cheap enough compared to existing TLC products, but we've already done this dance when TLC first arrived on the scene and people were stalwart about sticking to MLC drives only. Today? We got high-end NVMe TLC drives with better read/write and random IOPS performance compared to the best MLC SATA3 drives back when MLC was the superior technology.

    Yeah, it's going to take time for QLC to come down in price, the tech is newer and yields are lower, and companies are trying to fine tune the characteristics of their product stacks to make them both appealing in price and performance. Give it some time.
  • romrunning - Thursday, November 8, 2018 - link

    Sure, we lost endurance and speed with the switch from MLC to TLC. But the change from TLC to QLC is much worse in terms of latency, endurance, and just overall performance. Frankly, the sad part is that the drive needs the pseudo-SLC area to just barely meet the lowered expectations for QLC. Some of those QLC drives barely beat good SATA drives.

    We now have a new tech (3D Xpoint/Optane) that is demonstrably better for latency, consistency, endurance, and performance. I'd rather Micron continue to put the $ into it to get higher yields for both increased density/capacity & lower costs. That's what I want on the NVMe side, not another race to the bottom.
  • JoeyJoJo123 - Thursday, November 8, 2018 - link

    Sorry, you're not the end consumer that dictates how products get taped out, and honestly, if you were in charge of product management, you'd run the company into the ground focusing on making only premium priced storage drives in a market that's saturated with performance drives.

    The bulk of all SSD sales are for lower cost lower storage options. There is no "race to the bottom", it's just some jank you made up in your head to justify why companies are focusing on making products for the common man. Being able to move from an affordable 500GB SSD on TLC to an similarly priced 1TB SSD in a few years is a GOOD THING.

    If you want preemium(tm) quality products, SSDs with only the HIGHEST of endurance ratings for the massive Read/Write workloads you perform on your personal desktop on a day-to-day basis, SSDs with only the LOWEST of latencies so that you can load into Forknight(tm) faster than the other childerm, then how about you go buy enterprise storage products instead of whining in the comments section of a free news article. The products you want with the technology you need are out there. They're expensive because it's a niche market catered towards enterprise workloads where they can justify the buckets of money.

    You keep whining, I'll keep enjoying the larger storage capacities at cheaper prices so that I can eventually migrate my Home NAS to a completely solid state solution. Right now, getting even a cheap 1TB SSD for caching is super-slick.
  • romrunning - Friday, November 9, 2018 - link

    "...how about you go buy enterprise storage products instead of whining in the comments section of a free news article."

    You are taking this way too personally.

    I'm actually thinking more about the business side. I want 3D-Xpoint/Optane to get cheaper & get more capacity so that I can justify it for more than just some specific servers/use-cases. So I'd like Micron to focus more on developing that side than chasing the price train with QLC, which is inferior to what preceded it. With Micron buying out Intel's stake in IMFT for 3D-Xpoint, I just hope the product line diversification doesn't lessen the work to make 3D-Xpoint cheaper & even greater capacities.
  • JoeyJoJo123 - Friday, November 9, 2018 - link

    >You are taking this way too personally.

    Talk about projecting. Micron is taping out dozens of products across different product segments for all kinds of users. They're working on 3D-Xpoint and QLC stuff simultaneously and independently from each other. What's happening here is that Micron is producing QLC NAND for this Crucial M.2 SSD, and you're here taking it personally (and therefore whining in a free news article comments section) that Micron isn't focusing enough on 3D-Xpoint and that supposedly their QLC is bad for some reason. Thing is, this news article isn't for you. This technology isn't for you. You decided your tech needs are above what this product is aimed for: affordable, large volume SSDs for lower prices.

    Seriously, calm down. This wasn't an assault orchestrated by Micron against people that need/want higher performance storage options. More 3D-Xpoint stuff will come your way if that's the technology you're looking forward to. Again back to my main point, it's going to take some time for these newer technologies to roll out. Until then, don't whine in comments sections that X isn't the Y you were waiting for. If the article is about technology X, make a half-decent effort keep to the topic about technology X.
  • mathew7 - Tuesday, November 13, 2018 - link

    "I'll keep enjoying the larger storage capacities at cheaper prices so that I can eventually migrate my Home NAS to a completely solid state solution."
    Wwwwwhhhhhhhaaaaaaaaaaattttt?? NEVER. You don't understand the SSD limits. I would not do that with SLC (assuming current quality at QLC price).
    Enterprises with SSD NASes only use them for short-term performance storage with hourly/daily backup. Anyone who uses them differently is asking for a disaster.
    Look for linuxconf Intel SSD. There is a presentation where they explain how reading a cell damages nearby cells and manufacturers need to monitor this a relocate the data that is only read.
    I have 2 servers with only 1 SSD each for OS and 8-10TB HDDs for my actual long-term data.
    All my desktops/laptops have SSDs (Intel 320, Samsung 830-860 evo+pro, Crucial BX100/MX300 etc). But anything important on SSDs will be backed-up to HDDs.
  • Oxford Guy - Thursday, November 8, 2018 - link

    "That's what I want ... not another race to the bottom."

    That's what consumers want: value.

    That's not what companies want. They want the opposite. Their wish is to sell the least for the most.
  • Mikewind Dale - Thursday, November 8, 2018 - link

    "[Companies] want the opposite. Their wish is to sell the least for the most."

    Not true. Companies want to maximize net revenue, i.e. total revenue minus cost.

    Depending on the elasticity of demand (i.e. price sensitivity), that might mean increasing quantity and decreasing price.

    A reduction in quantity and an increase in price will increase net revenue only if demand is elastic.

    But given the existence of HDDs, it makes sense that demand for SSDs is elastic, i.e. price-sensitive. These aren't captive consumers with zero choice.

    Of course, nothing stops a company from catering to BOTH markets, i.e. high performance AND low cost markets.

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