Comparing Two 1TB NVMe Drives with Same NAND, Same Controller: XPG SX8200 Pro vs HP EX950
by Billy Tallis on February 6, 2019 11:30 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.
| HP EX950 and ADATA SX8200 Pro NVMe Power and Thermal Management Features |
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| Controller | Silicon Motion SM2262EN | ||
| Firmware | HP EX950: FWR1106C ADATA SX8200 Pro: R0906B |
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| 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 | 75 °C | |
| Critical Temperature | 80 °C | ||
| 1.3 | Host Controlled Thermal Management | Supported | |
| Non-Operational Power State Permissive Mode | Not Supported | ||
The HP EX950 and ADATA SX8200 Pro use different firmware version numbering schemes, but they report identical power and thermal management capabilities. The only change relative to SM2262 drives and the SM2262EN engineering sample we reviewed last year is that the warning temperature threshold has been increased from 70 degrees to 75 degrees. The critical temperature threshold is still 80 degrees. The power state table hasn't changed at all, and still advertises very quick transitions in and out of both sleep states.
| HP EX950 and ADATA SX8200 Pro NVMe Power States |
|||||
| Controller | Silicon Motion SM2262EN | ||||
| Firmware | HP EX950: FWR1106C ADATA SX8200 Pro: R0906B |
||||
| Power State |
Maximum Power |
Active/Idle | Entry Latency |
Exit Latency |
|
| PS 0 | 9.0 W | Active | - | - | |
| PS 1 | 4.6 W | Active | - | - | |
| PS 2 | 3.8 W | Active | - | - | |
| PS 3 | 45 mW | Idle | 2 ms | 2 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.
The retail SM2262EN drives have fully functional power management, unlike the engineering sample we tested last year. Both the ADATA SX8200 Pro and HP EX950 continue the trend of Silicon Motion-based NVMe drives having excellent power management. The active idle power draw is second best among high-end NVMe drives, behind the Phison E12 controller represented here by the Corsair MP510. The Silicon Motion drives achieve better deep sleep power savings than any other NVMe drives can manage on our desktop testbed.
The downside to the excellent idle power management offered by the SM2262EN controller is that it takes quite a while to wake up—60 to 80 milliseconds, slightly longer than earlier Silicon Motion NVMe controllers, and ten times longer than what the drive's firmware claims. This can hurt responsiveness when the OS chooses to be very aggressive about transitioning the drive into lower power states based on inaccurate information about how quickly the drive can get back to work.
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wolfesteinabhi - Wednesday, February 6, 2019 - link
this is a bit of worrying trend where we are getting same products with new/updated firmware...the firmware that was essentially free earlier...and get improved performance...now they have to pay and buy new hardware for it.ERJ - Wednesday, February 6, 2019 - link
When is the last time you updated the firmware on your hard drive? RAID card / BIOS / Video Card sure, but hard drive?Now, you could argue that the controller is essentially part of the hard drive in this case but still.
jeremyshaw - Wednesday, February 6, 2019 - link
Hard drive? They aren't that old, right? You do remember HDD firmware updates. As for SSDs, I've recently updated the firmware on my SSDs. Heck, even my monitor has been through a firmware update. Like the SSD updates, the monitor firmware affected performance and compatibility.jabber - Thursday, February 7, 2019 - link
I used to worry about SSD firmware updates when I was getting in 1 every blue moon and it had novelty value but 200+ SSDs later I now just don't bother. At the end of the day getting an extra 30MBps just isnt the boost it was all those years ago.ridic987 - Wednesday, February 6, 2019 - link
We are discussing SSD's not hard drive. Literally the thing what he is saying most applies to.Samus - Thursday, February 7, 2019 - link
I agree, the lack of SSD firmware updates - particularly what WD has pulled with the Black SSD's - is troubling. To artificially limit product improvement through restricting software updates and requiring the user to purchase an entirely new product sets a bad precedent. They could at least do what HP does in the server market and charge for support beyond the warranty. After a server warranty is up (typically 3 years) you have to pay for firmware and BIOS updates for servers. This isn't a terrible policy, at least it wasn't until meltdown\spectre hit and all the sudden it seemed somewhat necessary to update server firmware that were many years old.Hard drives get firmware updates all the time - just not from the manufacturers. They typically applicable to retail products for reasons. But go ahead and look up a random OEM PC's drivers from Dell or HP and you might see various firmware updates available for the hard disk models those PC's shipped with.
Are they important though? Rarely. Barring any significant bug, hard disks have little to benefit from firmware updates as they are so mechanically limited and the controllers are generally quite mature, having been based on incremental generations of past firmware. This could all change as MAMR and HAMR become more mainstream, the same way the only hard disk firmware I remember being common were the WD Black2 (the SSD+HDD hybrid) and various Seagate SSHD's - for obvious reasons. The technology was new, and there are benefits to updating the SSD firmware as improvements are made through testing and customer feedback.
melgross - Thursday, February 7, 2019 - link
I think of it the other way around. Unless there’s a serious bug in the firmware, firmware upgrades are a gift, that manufacturers don’t have to give.The fact is that even when they are available, almost no one applies them. That’s true even for most who know they’re available. It’s alwasys dangerous to upgrade firmware on a product so central to needs. If there’s an unfounded bug in the new upgrade, that could be worse than firmware that’s already working just fine, but isn’t quite as fast as you might wish foe.
I’ve never seen any major upgrade in performance from a drive firmware upgrade. Ever.
FullmetalTitan - Thursday, February 7, 2019 - link
Those of us around for sandforce controllers remember well the pains of updating SSD firmware to make our drives useableDigitalFreak - Wednesday, February 6, 2019 - link
Billy - how far are we away from having 4TB M.2 NVMe drives?Billy Tallis - Wednesday, February 6, 2019 - link
Most SSD vendors could produce 4TB double-sided M.2 drives using off the shelf parts. Putting 4TB on a single-sided module would require either going with a DRAMless controller, stacking DRAM and the controller on the same package, or using 1Tb+ QLC dies instead of TLC.So currently any 4TB M.2 drive would have at least some significant downside that either compromises performance, restricts compatibility, or drives the price up well beyond twice that of a 2TB M.2 drive. There's simply not enough demand for such drives, and likely won't be anytime soon.