How big, how fast and how reliable? Boil the solid-state storage buying procedure right down, and these are the three key questions you need to be asking.
It sounds simple enough, but as soon as you pop open Pandora's SSD box, the complexities come bursting out. How fast, you ask? Do you mean sequential read and write performance? What about random access? And hang on - if you're wondering about sequential performance, are you talking compressible or incompressible data?
Sure, there are nuances when it comes to processor or graphics performance, like single-threaded versus multi-threaded performance on a CPU, but there aren't quite so many dramatic contrasts.
There's loads to keep track of in terms of technology too, from controller tech to memory types and storage interfaces. All of that makes solid-state storage seem daunting, but it's still the most exciting thing happening to the PC. It's the final frontier of performance - the wild west of components - and the latest wave of SSDs look like the best yet.
That exciting edginess is both a bane and a boon. You can't just fire up any old SSD and expect it deliver indefinitely. It's more complicated than that. Unlike CPUs, for example, solid-state storage still isn't a fully mature technology. It's riskier and more unpredictable. Quite frankly, it's a bit more fun.
If you don't already have an SSD, it's likely that an upgrade to solid-state will do more to transform the feel of your PC's day-to-day performance than anything else. If you have an early SSD, you might be surprised at just how far the game has come in the last couple of years.
So we've brought 10 of the best new SSDs together. There have been some hot developments in terms of capacity and performance in recent months, along with a new contender in the all-important controller market.
There's plenty to ponder. Capacity. That's the real headache when it comes to solid-state drives, not performance or reliability, though both of those can be patchy. Nope, it's plain old storage capacity that prevents SSDs from being no-brainers.
As we write these words, a conventional 1TB hard drive can be had for about £50. The cost for a similarly capacious SSD? We could only find one non-PCIe example: the OCZ Octane 1TB, listed at £1,812. It's frankly offensive. Hell, you can have a 2TB hard disk for about £70 and a 3TB beast for about £100. When it comes to conventional magnetic drives, the cost of storage is fast approaching free.
Now, our argument has often been that you can get by with a relatively small SSD if you combine it with a conventional drive for mass storage, and that's true up to a point, but as the years tick by, it's a compromise we're less and less keen on making.
The biggest problem is games. A half decent Steam library, for instance, soaks up hundreds and hundreds of gigabytes. Realistically, that means either picking and choosing how many games you have installed at any one moment, or sticking the whole shebang in mass storage. Either way, the argument for SSDs is instantly that little bit weaker.
What we really want are SSDs big enough to swallow all our performance-critical data without having to even think about it, but when's it going to happen?
Price wars
Earlier this year, we saw perhaps the biggest ever price drop in solid-state storage. Prices for drives in the 120GB to 128GB range suddenly plummeted from around £120 to nearer £70.
Why did it happen? Partly it's ye olde supply and demand. For starters, a glut of DDR memory chips annihilated RAM prices. Most SSDs have some RAM, so that all-important bill of materials was lowered.
Of course the flash memory chips are the real expense, and a combination of new production facilities along with shrinking production tech contributed to significant price drops there, too.
But there's also another theory - a more sinister notion. The scuttlebutt is that the big players in the SSD market want to squeeze out the little guys, so they've triggered a price war that the smaller solid-state operators simply cannot sustain. Who's behind this - if indeed it's happening at all - isn't clear, but the SSD market certainly has some major imbalances.
Samsung, for instance, made a profit of $7 billion in its most recent quarter. That's $7 billion in three months. Over the same period, OCZ made a loss on revenues of $113 million. Talk about David and Goliath.
You might think it's all gravy so long as SSD prices go down, but what happens when all the little guys are dead? Will the big beasts be so keen to keep prices low? It's something to think about, at least.
With all that in mind, it's somewhat ironic that Samsung is the one pushing the envelope in terms of technologies that should give SSD pricing another boot to the soft and danglies. Its new 840 series SSD is the first to use TLC (triple-level cell) memory, increasing data density by 50 per cent at a stroke.
At the same time, the South Korean company has pushed on to 21nm silicon production for its latest flash memory cells. You can read more about the 840 overleaf, but suffice to say the combination of TLC memory and 21nm flash should soon translate in record lows for SSD cost per gigabyte.
Realistically, we're still several years away from affordable multi-terabyte drives, but SSDs in the 240GB to 256GB range are increasingly affordable, and if you can live with 128GB, there are some real bargains to be had.
Solid performance
As for SSD performance, three interrelated subjects are currently in vogue. First of all, there's a new entrant into the SSD controller market in the form of Link A Media Devices. Corsair is the first SSD maker to jump in with LAMD.
Another controller-related issue is IOPS performance, or how many input/output operations a drive can manage. Arguably, it's IOPS performance and not measures of peak throughput that really defines how responsive a drive feels, subjectively speaking.
That said, the huge sequential throughput of the latest SSDs is creating problems of its own, which brings us to the third SSD performance issue of the moment: the interface bottleneck.
Even the SATA 6Gbps setup isn't quick enough for the latest drives. That's why we're seeing peak sequential performance benchmark results bunch up at a little over 500MB/s. The interface doesn't really allow for more.
As capacities rise and larger drives drop into affordability, the impact of capacity on performance becomes more relevant too. The specific issue here involves memory channels, the number of chips attached to each one, and keeping those channels busy. You can find out more about that in our individual drive reviews, but the good news is that larger drives tend to perform better.
The final part of the SSD puzzle is reliability. The introduction of the TRIM command with Windows 7 made things much less scary, and stuttery SSDs are mostly a thing of the past. That said, the introduction of Samsung's TLC, or triple-level cell memory, does reignite the reliability debate to an extent.
TLC can't cope with as many write cycles as MLC memory, which is one reason why Samsung is now quoting mean-time to failure for its new SSDs, rather than how many cycles the memory chips are good for. It's a complicated issue when you factor in things like write amplification. Send the same data to two different drives and you'll get a very different number of writes.
Anyway, the point is that SSD reliability isn't quite a done deal, but don't let that put you off. There are some great drives here, some of which are available for very attractive prices. If you haven't already gone solid or if you're putting up with an early, stuttery SSD, now's the time.
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