SSDs Not as Reliable As 1TB HDDs

That’s something I have suspected all along, but I’ve only expressed it a couple of times, because so many places were extolling the virtues of SSDs like they were getting a piece of the action. (Hmmm, perhaps they were.)

The nice thing about some places on the internet is that you can count on the unvarnished truth at all times. The news may not be pleasant, but it’s the truth. John Dvorak tells it like it is, whether you like it or not. It’s what has given him a life beyond the pages of PC Magazine. Robin Harris, of ZDNet, is another longtime industry insider that will never sugar coat the truth or put it aside for the sake of convenience.

So it was no surprise when his entry for this last week was the notice that solid storage (flash, after all) was not as reliable as a technology that has over thirty years of improvements on its side.

In his entry he explains why it is so, beyond the number of cycles expected for flash memory, which is due to the rather large fluctuations in voltage the individual cells see as a result of the writing process.

These findings are surprising if you consider flash chips to be like the thousands of other integrated circuits that you use every day. IC reliability is impressive and it is not uncommon for a chip to work flawlessly for a decade or more.

But flash chips aren’t like other chips: they require ≈20 volts to write data. In the chip world, where insulating layers may only be a few molecules thick, 20 V is a lot of electrical pressure.

Wait a minute, you might think, there isn’t a single flash chip that specifies a 20 V or even in 15 V power requirement. And you would be correct.

Flash chips have power specs like other chips. What’s different is that flash chips have on-board electrical pumps – in the form of dedicated capacitors and an oscillator – that take supply voltage and convert it to the higher voltage needed to write a flash cell.

With that in mind, and the fact that the difference between working voltage and the voltage needed to write or erase a cell, it is easily seen that the stresses could cause early failure on a consistent basis. It is why I never fully trust any other flash drive technology, and why when others are screaming for no more optical discs it’s easy to see why they have not really thought that  idea through. (It may also be that my first encounters with keychain drives was not fortunate, as they all failed spectacularly, at the worst time.)

Can you imagine software being routinely released on flash drives, instead of optical media? It’s a scary thought for me; of course, companies like Microsoft probably love the idea – for them it’s only slightly less magnificent than if we went back to releasing software on floppy disks. The replacement media business would be tremendous, not to mention the number of people having to repurchase software, because they lost the paperwork noting the original sale.

The real bottom line of this is the same as it was thirty years ago, when hard drives stated getting inexpensive and expansive – data is like liquid, and once spilled (lost), it is not possible to do anything but cry. So backup should be like going to Sunday school, religiously done.

Data duplication over several places is the only way to avoid data loss, so perhaps with that shiny new computer you just got the family, a good data backup routine should be established.

If you want to be lazy about it, and have an internet connection that is better than dial-up, you could use one of the free online options, such as SugarSync.

May your data live long and prosper!

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