Every time we think we've cracked this SSD testing lark, it just gets tougher.
In the early days, it was all about raw sequential grunt. Then it became clear that drives performed differently with compressible and incompressible data, so that had to be factored in.
Of course, real-world PC performance depends on much more than mere sequential throughput, so random access performance was stirred into the mix. Bung in some actual application tests and we were beginning to think we had a pretty good feel for overall drive performance.
And so we were, but only at a given moment in time, and a given state of drive usage and wear. Unfortunately, the reality is that fully torture-testing every solid-state drive we review to destruction is impractical. We'd need months if not years with each drive, and by the time we finally published our results, the model in question would probably have disappeared.
However, what we've added to our standard battery of tests this time around is an extra endurance test. We always fill and then empty each drive of data before testing, but this time we added another two fill-and-delete cycles, then compared the drives' before and after performance. The results are certainly interesting.
And the winner is… OCZ Vertex 4 256GB
Things change fast in SSD land. A year ago, it was all about previously little known outfit SandForce. Today, SandForce isn't exactly dead, but the competition is significantly more lively.
What's really interesting, however, is the mix of players and technologies involved. On one hand you have the likes of Samsung, the megabeast of tech, pushing the envelope with its new triple-level cell memory and fourth generation in-house controller. On the other, you've got relative minnow OCZ cooking up a remarkably competitive alternative with its own Indilinx controller technology.
Then there's a whole bevy of players pulling together interesting SSDs using a mix of off-the-shelf tech and some agile thinking. It's all very different from CPUs and graphics cards, where two major players dominate the key technologies. For the most part, that makes the SSD market more fun, vibrant and competitive.
Test of time
But there's another side to the wild west of SSDs, and that's the frustrating fact that performance and reliability remain patchy. With the best will in the world, it's hard to know how reliable any SSD is going to be, or how well its performance will hold up with heavy usage.
To be clear, a lot of progress has been made. The awful, stuttery drives of a few years ago are history, but we're not yet at the point where SSDs just work - where you can choose based on simple metrics of price and performance. Choosing a pecking order for this batch of SSDs isn't easy, but a few are immediately defenestrated due to wonky performance numbers or silly pricing.
The first to go is KingSpec's epic 1TB PCIe card. In some tests it delivers the 2GB/s goods. In others, it's slower than a £70 SSD. That's not nearly good enough given the £1,000 sticker.
Other losers are the Plextor M5 Pro, KingSpec E3000 and Corsair Neutron GTX. Whatever you say about them - and the Plextor and Corsair are good drives - they're simply too expensive.
Kingston's HyperX 3K takes an early bath due to poor application performance.
From here on in, the competition is very close. In fact, it's even closer than our scoring suggests. That's because we've included a wide range of metrics in our reckoning. But it's entirely legitimate, for instance, to favour reliability above all else, in which case an older, proven drive not in this group - like Samsung's 830 - might get the nod.
With that in mind, you might find Intel's 330 Series compelling. Nobody does more validation work than Intel. Then again, Corsair's Neutron balances performance and price pretty nicely, as does Samsung's new 840, though you'd arguably give Samsung the benefit of the doubt regards reliability.
That leaves us with two drives: Sammy's new 840 Pro and the OCZ Vertex 4. If there's ever been a tighter finish on a group test here on PC Format, we can't remember it.
You can make strong arguments for both drives. The 840 Pro is super quick and comes with Samsung's outstanding record for SSD endurance, but the Vertex 4 is even quicker, and dirt cheap.
The choice comes down to your attitude towards risk. The Vertex 4 has a five-year warranty, so if the worst happens, you're covered. But a loss of data can be worse than the cost of a drive, and we have first-hand experience of failing Vertex 4s.
So good is the Vertex 4's performance (and that includes our endurance test), we feel compelled to give it top honours, but even so we still find it hard to ignore an older, proven SSD. You pays your money. You takes your choice.