Clue, mobile edition: the case for the missing SSD power savings


SandiskssdWe’ve been talking about SSD, or flash-based solid-state drives for a good year or two here. Lately, there’s been some question on one of the key advantages SSD drives are supposed to have over traditional magnetic storage. Yes, they can potentially read / write data faster in some cases, decrease boot times, and they also have no moving parts to wear out or break. But we mobile device users are constantly grappling with battery life, so like many others, I was surprised to read that Tom’s Hardware testing showed less battery life with SSD drives. LAPTOP Magazine countered with tests of their own showing that the units they used actually did eek out a little more battery life.

Who’s right and who’s wrong? I suspect that both are right or wrong depending on device configurations and usage models. While we do benchmarking here for some devices, this illustrates the key reason why we only publish them to be used as general guidelines. Remember: personal computing is exactly that; personal. I could be happy with the performance of a device while you might find it to not meet your needs. And replicating two exact devices and configurations between two different users? Practically impossible.

Having said that, I still believe in SSD as a key mobile device component once we get a much lower cost-per-gig. Multi-level cell technology will help in that area and we should see SSD prices continue to trend downward much faster in the next year as a result. Battery life? I don’t think SSD technology alone will solve our battery challenges, but they really shouldn’t hurt them either. And maybe I’m over-simplifying here, but if both an SSD’s idle and active power consumption is less than a magnetic drive’s idle power usage, the law of averages generally tells me that the SSD drive will use less power overall when compared to that traditional drive (unless it’s much slower in terms of data transfer, perhaps?). Again, I might be off-base there, but I know you folks will keep me honest with your opinions.

(via Small Laptops and Notebooks)



Well, they’re both right. Tom’s Hardware identified a scenario where SSD based devices have a noticeably shorter battery life. Laptop identified a scenario where SSD based devices have a slightly longer battery life. Unless you can find an error in their procedures, it’s hard to dispute their results for their given scenarios. The debate is over which of these scenarios is more likely.

I doubt anyone will run anything on their portable computer that stresses it continuously for hours at a time without a break. If that’s what you do with your laptop, then, yes, SSDs are likely a bad deal for you. At least you’ll get as much computation done in that shorter amount of battery life.

That’s not how most people use their laptops. For most people, their portable computing device is idle much of the time. This puts HDDs at a disadvantage because it has to spin up, then spin back down. It ends up getting used more than the SSD.

Tom’s Hardware did a disservice in that they never examined how likely the average laptop user would run into the scenario they set up. They’re right that “no one turns the notebook on just to wait around until the battery runs empty.” However, few, if anyone, stress their laptops as hard as Tom’s Hardware did in their testing.

That said, I doubt there are many scenarios where this generation of SSDs offer significantly longer battery life than HDDs


From my personal experience SSD are clear winners over 4200 RPM drives. They are just too slow for Vista. Their long seek times block for too long the scheduler and this makes the whole device very laggy. They make also coming back from standby and loading an application much faster.

In the end too much of the battery life is wasted in waiting for the device.

Conclusion: I have less problems to get through the day with a single charge.



Does Vista really operate with that?
I heard performance of these adapters is horrible … so much so that the OS is unusable (4-5 hour installation times, etc.)

Hoo-Chuan Tan

With how I’ve seen people use their computers, and the way how Windows Defrag (XP or Vista) operate, SSD is probably the better option overall, but not by much.

I’ve you’ve got a third party defragmentation tool that can do proper smart placement of files on the drive platters, then HDD would probably win since there’d be less time with the drive in seek mode.

Of course, with a high performance SSD, if it had the same power characteristics, it’d probably win out in all situations.


Eschewing the $$$$ for a “real” SSD I upgraded my Motion Computing LE1700 using a RiData 32GB Compact Flash Card and a $3 eBay from Hong Kong ZIF 1.8″ HDD to Compact Flash adaptor board. Total cost (with shipping): $150.

Since the compact flash card is not designed to vampire a Nikon DSLR’s battery you do get power savings. I’m seeing an extra half hour or so of run time using the notorious power hog: Vista Ultimate.

Performance is good with it putting the missing zip into Vista, enabling me to upgrade from XP (which I had stuck with due to Vista’s lethargic performance on the 1.8″ HDD).

James Kendrick

What strikes me about all of these benchmarks is that the very least the battery savings (if any) of using an SSD over a HDD are much smaller than we originally thought. While SSDs should still provide a good performance boost for mobile PCs over their spinning siblings without the perceived battery life savings it will be a very long time indeed before adoption equals higher cost.

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