Hard disks and flash storage will co-exist – for the moment

When it comes to personal storage, flash is now the default technology. It’s in your phone, tablet, camera, and increasingly in your laptop too. Is this about to change?

I’ve installed solid-state disks in my laptops for the last three or so years simply because it means they fire up very quickly and – more importantly – battery life is extended hugely. My Thinkpad now works happily for four or five hours while I’m using it quite intensively, where three hours used to be about the maximum.

The one downside is the price of the stuff. It remains stubbornly stuck at 10x or more the price per GB of spinning disks. When you’re using a laptop as I do, with most of my data in the cloud somewhere and only a working set kept on the machine, a low-end flash disk is big enough and therefore affordable: 120GB will store Windows and around 50GB of data and applications.

From a company’s point of view, the equation isn’t so different. Clearly, the volumes of data to be stored are bigger but despite the blandishments of those companies selling all-flash storage systems, many companies are not seeing the benefits. That’s according to one storage systems vendor which recently announced the results of an industry survey.

Caveat: industry surveys are almost always skewed because of sample size and/or the types of questions asked, so the results need to be taken with a pinch – maybe more – of salt.

Tegile Systems reckons that 99 percent of SME and enterprise users who are turning to solid state storage will overpay. They’re buying more than they need, the survey finds, at least according to the press release, which wastes no time by mentioning in its second paragraph that the company penning the release just happens to have the solution. So shameless!

Despite that, I think Tegile is onto something. Companies are less sensitive to the price per GB than they are to the price / performance ratio, usually expressed in IOPS, which is where solid-state delivers in spades. It’s much quicker than spinning disks at returning information to the processor, and it’s cheaper to run in terms of its demands on power and cooling.

Where the over-payment bit comes in is this (from the release): “More than 60% of those surveyed reported that these applications need only between 1,000 and 100,000 IOPS. Paying for an array built to deliver 1,000,000 IOPS to service an application that only needs 100,000 IOPS makes no sense when a hybrid array can service the same workload for a fraction of the cost.”

In other words, replacing spinning disks with flash means you’ve got more performance than you need, a claim justified by the assertion that only a small proportion of the data is being worked on at any one time. So, the logic goes, you store that hot data on flash for good performance but the rest can live on spinning disks, which are much cheaper to buy. In other words, don’t replace all your disks with flash, just a small proportion, depending on the size of your working data set.

It’s a so-called hybrid solution. And of course Tegile recommends you buy its tuned-up, all-in-one hybrid arrays which saves you the trouble of building your own.

Tegile is not alone in the field, with Pure Storage having recently launched in Europe. Pure uses ordinary consumer-grade disks, which should make it even cheaper although price comparisons are invariably difficult due to the ‘how long is a piece of string?’ problem.

There are other vendors too but I’ll leave you to find out who they are.

From a consumer point of view though, where’s the beef? There’s a good chance you’re already using a hybrid system if you use a recent desktop or laptop, as a number of hard disk manufacturers have taken to front-ending their mechanisms with flash to make them feel more responsive from a performance perspective.

Hard disks are not going away as the price per GB is falling just as quickly as it is for flash, although its characteristics are different. There will though come a time when flash disk capacities are big enough for ordinary use – just like my laptop – and everyone will get super-fast load times and longer battery life.

Assuming that laptops and desktops survive at all. But that’s another story for another time.