The Mainstream Phoenix Rises: Samsung's 970 EVO (500GB & 1TB) SSDs Reviewed
by Billy Tallis on April 24, 2018 10:00 AM ESTPower 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.
| Samsung 970 EVO NVMe Power and Thermal Management Features |
|||
| Controller | Samsung Phoenix | ||
| Firmware | 1B2QEXE7 | ||
| 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 | 85°C | |
| Critical Temperature | 85°C | ||
| 1.3 | Host Controlled Thermal Management | Supported | |
| Non-Operational Power State Permissive Mode | Not Supported | ||
The Samsung 970 EVO bumps the supported NVMe spec version to 1.3, compared to the 1.2 feature set supported by the PM981 and 960 series. The 970 EVO implements the Host Controlled Thermal Management feature, allowing operating systems to configure the drive to throttle at a lower temperature than it normally would. The (optional) non-operational power state permissive mode feature is not included, so the 970 EVO is not supposed to do background tasks like garbage collection when it is in idle power states (unless they can be done within the power constraints of the idle states, which is unrealistic).
| Samsung 970 EVO NVMe Power States |
|||||
| Controller | Samsung Phoenix | ||||
| Firmware | 1B2QEXE7 | ||||
| Power State |
Maximum Power |
Active/Idle | Entry Latency |
Exit Latency |
|
| PS 0 | 6.2 W | Active | - | - | |
| PS 1 | 4.3 W | Active | - | - | |
| PS 2 | 2.1 W | Active | - | - | |
| PS 3 | 0.04 W | Idle | 0.21 ms | 1.2 ms | |
| PS 4 | 0.005 W | Idle | 2 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 draw of the 970 EVO seems to be about 20% higher than the preceding generation of Samsung drives, but the low-power idle we measured is about the same as most other high-end NVMe drives.
The idle wake-up latency of the 970 EVO is more than twice that of its predecessors and also significantly higher than that of the Samsung PM981. This ~14ms latency exceeds the 8ms that the drive itself claims as its latency to wake up from its deepest sleep state.
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mapesdhs - Sunday, May 6, 2018 - link
HollyDOL, as others have said, it very much depends on what you're doing. As a C-drive it simply helps to have any kind of SSD at all rather than a rust spinner (except of course the cheap junk knockoffs like Gloway). The Vertex3 was a pretty good SSD for its time (I have lots of them), though back then the Vertex4 presented its own significant bump up in benchmark performance, as did the Vector. For general use, you might notice some difference compared to an NVMe device, certainly in bootup times, but beyond that it depends on the task. Some games will certainly load a lot quicker, assuming the CPU/RAM are able to take advantage of it. And btw, some older mbds can have a mod BIOS installed to enable booting from NVMe (I'm more familiar with the options for ASUS boards in this regard), and certain NVMe SSDs even have their own boot ROM (eg. 950 Pro) such that native boot support isn't required.It's a good idea for video editing though, eg. the main cache/scratch drive for After Effects or Vegas.
Lolimaster - Tuesday, April 24, 2018 - link
Unless you work moving huge chunks of data (editing 4k for example) a lot there's no point going NVME over the Crucial MX500 sata.Death666Angel - Tuesday, April 24, 2018 - link
Especially in cramped cases, small form factor stuff, the gum stick is really nice because you don't need annoying cables around. My next MoBo will be some Ryzen thing in mATX with 2 M.2 slots (likely PCIe and SATA), so I can go all SSD for my desktop without any cables. I haven't noticed improvements after going to SATA3 SSDs from my Vertex/Agility first gen ones.iwod - Saturday, April 28, 2018 - link
I can't disagree more. SATA is limited in Seq speed. And it is actually a user observable difference in everyday use, between a 1.5 - 2GB/s and 600MB/s speed.Now whether that is worth a little more money you paid for is a different question.
peevee - Monday, April 30, 2018 - link
And how you are going to hit the seq speed in real life? All external (USB or network) sources and targets are slower. Writing does not matter with write-back OS caching. Reading a document into memory is limited by memory size and actually parsing/decompression of the document. Unless you are copying huge files between RAM drives and your SSD, you have no use case. That is why the tests are generating random data on the fly, like NOTHING does in real life. And that is why sites like AT have NO reproducible real-life tests (like compilation of a large software package for example, or recoding of video), as they would show about 0 real difference between drives 2x in price.mapesdhs - Sunday, May 6, 2018 - link
I see a nice difference when cloning my photo/video archive (1TB SM961), moving files around, network access, etc., to the extent I'm now looking into 10GigE.Lolimaster - Tuesday, April 24, 2018 - link
You don't see everyday benefits because the things that make SSD's faster than HDD's (access times, random 4k QD1 reads) barely improves from sata to nvme. Even with an optane SSD you won't see much improvement.Lolimaster - Tuesday, April 24, 2018 - link
1-SSD had 100x less access time vs HDD and 100x higher 4k random performance, NVME basically only improves on sustained transfer raters.Going from 5-10ms to 0.07ms and from 400KB/s to 40MB/s~ was a lot.
Cooe - Tuesday, April 24, 2018 - link
Yup. Without a doubt a good NVMe is much snappier, but you have to be the right kind of PC user for the difference to be that level of obvious. Even the heaviest applications, projects, etc... open instantly or near it vs the usual couple seconds, up to a minute or so for the really beefy crap with SATA-III, so if you're well familiar with PC's & in-tune with yours' level of performance, and are somebody who's regularly booting up, closing, and switching between multiple applications, storage heavy projects, etc... NVMe provides an obviously superior experience. And even if you aren't that kind of person yet, if you have compatible hardware the price gap has shrunk enough that I'd still recommend NVMe over SATA regardless as storage loads only ever increase with time. Aka you might not be the kind of person/PC user that can/will notice it now, but in a few years chances are that you most definitely will, and'll be glad you made the choice you did.For most lighter users atm otoh, SATA-III's already plenty fast enough for the workloads they regularly do. And that's on top of the fact that they simply don't have the level of "PC awareness" for the difference to stand out the way it does for heavy users and PC nerds like myself. And of course, even for us heavy users & multi-taskers who get real & significant benefits from the switch, it's still nothing on the order of the HDD to SATA SSD jump which is why those not well aware of their PC's current performance level and whom aren't heavy storage users (lots of regular & concurrent file access, movement, and modification) are rather likely to not notice the improvements w/o having them explictly pointed out (ala instantaneous or near it launches of most apps, even for multiples simultaneously vs delay's of a handful of seconds to a minute+ or so for the biggies, vastly improved file copy & movement speeds, ability to maintain SATA SSD levels of responsiveness while heavy storage workload(s) are active in the background, etc...)
Cliff34 - Tuesday, April 24, 2018 - link
For me, the higher premium prices for nvm ssd vs sata ssd is not worth for the performance gain. I'm sure a nvm ssd is faster but I don't want to shell out few hundreds dollars (comparing the 1td) more to have my computer a few seconds faster.