is there really this much difference in power consumption among NVMe SSD's?

ginahoy

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Apr 23, 2008
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I'm planning my next PC with the goal of making it nearly silent during normal office use. My computing requirements are modest so I'm focused more on minimizing power & heat than maximizing performance. Today I'm researching 240GB SSD's.

I've been seeing complaints that some of the new NVMe drives are getting quite hot. The M.2 spec limits bus power to 7 watts, which may not sound like much, but it's enough to push temps to 80C and even 100C, presumably due to the small form factor.

Referring to power specs listed on newegg, I'm finding most NVMe ssd's have an active rating of 4 to 6 watts, about double the SATA III ssd's I checked. Although storage components spend a lot more time at idle, active power consumption is an important consideration for cooling system design and noise (fan) management (as well as device longevity, I would imagine). Given all the anecdotal reports of scorching hot ssd's, I was considering just going with a SATA III model.

Then I came across the WD Black ssd, which has an active power rating of a mere 135 milliwatts!! I assumed it was a misprint but WD's datasheet confirms this number. Then I saw another drive, the ADATA XPG SX8000, with an active power rating of only 333mW. What gives? All the other NVMe drives I checked have MUCH higher ratings. For example, the Samsung 960 EVO is rated at 5.3W active. I realize it has significantly better performance than the WD but I can't see how that would make a 40-fold difference in the power rating!

BTW, newegg doesn't list the power ratings for the highly touted MyDigitalSDD BPX. The product overview just says it consumes "less than 7W".

I suspect what's going on here is a lack of standards for how active power consumption is rated and reported. If so, I don't want to buy the WD Black for the wrong reasons (i.e., if reported power ratings aren't apples-to-apples). Can anyone here shed any light on this?
 

popatim

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WD's Active power spec is Average Active power, Average being the key word here. Notice them make no mention of in use power but I see peak power at 2.5A and at 3.3v that is just over 8w.
This Review claims the idle power draw is 404mw, thats pretty far from 135. Sadly Tom's does not measure power on their review.
 

ginahoy

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Yeah, I saw the 2.5A peak power rating on the spec sheet after posting. Notwithstanding the idle measurement in the review you posted, it makes no sense that the average active power, as per the spec, is a small fraction of a watt given that peak rating. Sigh.

Aside from power concerns, that review wasn't kind to WD, so back to square one.

I'm seriously thinking about just going with a SATA SSD since they're inherently more efficient.
 

ginahoy

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When I say SATA SSD is inherently more efficient, I'm referring to power consumption per unit of data transferred. I've seen this stated matter-of-factly in multiple sources, and is consistently reflected in notebook battery life testing published on this site.

I've also seen anecdotal reports that NVMe's superior performance has little impact on average users, especially someone like myself with modest computing needs. But what's most concerning is that it's apparently still the 'wild west' when it comes to active power management for NVMe drives (re: Billy Tallis reply here: http://bit.ly/2tM1dxT, and his discussion under Idle Power Consumption here: http://bit.ly/2tLOJGr).

Since I've never experienced a SSD, I'm sure a SATA drive will be plenty fast. By the time I'm ready to upgrade again, hopefully we'll see some maturity and uniformity in OS implementations of NVMe's ASPM features through SSD tools. I'll be running Linux on my new machine, another first for me, and I'm not yet up to the task of using low level commands to optimize power management for my primary storage media.
 

popatim

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I agree with you on the disparity of ASPM among the NVMe drives available, some don't even implement it at all I've heard.
I wish there were better reviews that covered power consumption better. On my own gaming laptop, an SSD made little difference in battery life when doing what i normally do which is usually editing or rendering videos so it can be very graphic and storage intensive loads. When your HDD does not have to spin up, its usually very power friendly at about 2 to 3w.