6 super-fast SSDs to speed up your PC
18th Sep 2009 | 08:30
Solid state of the art - all the fastest SSDs in one place
Solid state drives: Overview
When solid-state drives first hit the mainstream a year or so ago, it seemed the only problem was pricing.
After all, SSDs give conventional hard disks based on spinning platters a solid spanking by just about any metric you care to mention. For starters, SSDs typically boast hefty sustained data transfer capabilities and ultra-low seek times.
After the excruciatingly gradual performance improvements made by rotational hard drives over the years, therefore, flash memory technology is finally putting storage performance on the same path of relentless progress enjoyed by CPUs and graphics chips. Moore's Law comes to hard disks, in other words.
Thanks to a total absence of moving parts, SSDs are also much more robust and emit hardly any noise at all.
In short, they make for a much more modern solution to data storage than something that spins. If that's the theory regarding SSDs, however, the practice has so far been rather less auspicious.
Problems with SSD
After the early buzz surrounding SSDs dissipated it slowly become clear that something wasn't right. Simple tests of sequential data transfer speeds did indeed confirm the peak read and write speeds claimed by manufacturers were on the money.
But the actual user experience didn't jive with those eye-catching numbers, particularly when it comes to heavy use over an extended period. The initial sense of SSD speed was often replaced by strange system stalls and stutters.
What's more, some also questioned the longevity of solid state drives given the propensity for flash memory cells to wear out. All of which means the SSD has not quite been the messiah of storage solutions it first appeared.
Of course, nothing in the land of PC technology stays the same for long and the arrival of second and third generation SSDs, along with software upgrades to existing drives, has seen significant improvements.
With all that in mind, let's find out if the latest SSDs finally deliver on that early promise.
Low-end SSDs from £105 to £265
Kingston SSDNOW V Series 64GB - £105
+ Decent maximum data throughput
- Patchy real-world experience
- Awful random access performance
Ping any of the big online retailers for SSDs and you'll find a huge array of brands and models. Verily the solid state drive has entered the mainstream.
Consequently, prices are edging downwards daily, if not quite at the pace we'd like. The big question, therefore, is how much do you need to spend to get a decent SSD?
Making the argument for the entry level choice is Kingston's SSD Now V Series in 2.5-inch, 64GB trim.
In terms of both key performance metrics and capacity it's about as low as we would recommend you go.
Despite that, it still weighs in at a not insubstantial £105. Make no mistake, even modest SSDs remain painfully pricey. That's especially true in the context of the Kingston's stingy 64GB capacity.
After all, £100 will bag you 1.5TB's worth of rotational hard disk. Put another way, a conventional hard drive is no less than 23 times more cost effective when it comes to storage capacity. Yikes.
Still, at least the puny size kills stone dead any debate regarding the usage model for this sort of drive. It's not even close to being big enough for mass data storage.
Better instead to use it as a boot drive containing the operating system and key applications, while conventional magnetic disks do mass storage duties. For most people, 64GB will be enough for that purpose.
Problems for games
Those with large game libraries, however, might find themselves running out of space rather rapidly. Moreover, given the tendency for SSD performance to degrade when rammed to bursting with data, not to mention the fact that modern day-to-day PC usage can generate multiple gigabytes of garbage such as internet cache files and general desktop detritus, a 64GB limit is a potential irritation.
If you can live with that, the Kingston gives you an SSD with frankly mediocre sequential transfer rates.
Along with every other drive here, the V Series sports multi-level-cell (MLC) flash memory, in this case manufactured by Japanese electronics leviathan Toshiba. That makes for denser, cheaper memory chips.
But with peak sequential read performance of 100MB/s and writes of 80MB/s, they're not as fast as the MLC competition, much less single-level-cell (SLC) memory.
The other crucial part of any SSD is the controller chip. Here there's cause for further concern thanks to the presence of a controller based on the infamous JMicron design. Infamous, that is, for the stuttering problems that early SSDs suffered from.
The choice of this elderly controller is clearly a cost play. However, Kingston says it has been working closely with both JMicron and Toshiba to ensure a stutter-free performance.
Whatever the truth, the V Series comes in two packages, desktop and notebook. Both contain exactly the same 2.5-inch SSD with standard SATA connectors. The notebook version tested here sports both a handy USB enclosure and a copy of Acronis True Image HD.
The idea is that you use the USB enclosure and disk-cloning application to transfer an image of your hard disk onto the V Series before swapping it out. Overall, it's a nice package and looks good value compared to the next rung up in the SSD hierarchy, represented here by Corsair's P128.
Corsair P128 128GB - £265
+ Monster sequential read and write numbers
- 4K random writes are a worry
- Not exactly cheap
As the name suggests, this is a 128GB 2.5-inch drive with a £265 sticker. Boy do you pay dearly for the additional capacity.
In return, however, you receive the latest Samsung SSD technology with both flash memory and an ARM-based controller CPU supplied by the Korean giant. In fact, this drive is essentially a 128GB version of the uber-expensive 256GB Samsung PB22-J.
That means it boasts a so-called 'self healing' function that addresses the problem of residual data in memory blocks. How well this works is tricky to judge. The feature is said to kick-in only after a cold boot, with the system left to idle.
In any case, the claimed maximum read performance looks hot to say the least at 220MB/s. Even more impressive are the nearly symmetrical 200MB/s writes. That's huge for a drive based on MLC flash memory.
On paper, therefore, this looks like a bit of a mismatch, an impression backed up by our synthetic benchmarks. Despite returning an unexpectedly healthy sequential read result of 126MB/s, the Kingston drive lags well behind the 215MB/s peak read performance of Corsair's P128.
It's a similar situation in the write performance test, where 92MB/s plays 189MB/s.
However, more worrying are the 4K random write performance results. This test is designed to more closely simulate the sort of disk activity you get during normal PC use than sequential benchmarks and it makes for very ugly reading for Kingston at just 0.24MB/s. Frankly, the Corsair's 3.64MB/s result is hardly stellar, either. It's altogether rather worrying stuff.
Back in the real world, however, the gap is not so obvious. Subjectively, we think a hint of lag is detectable from the Kingston V Series in general use
But there's relatively little evidence of it in our real world benchmarks. It's just a second behind the Corsair drive in our game level load test and more or less matches several of the most expensive drives on test this month when it comes to in-game frame rates.
Similarly, it completes the file unzip test in one minute and 14 seconds, a reasonable result compared to the 58 seconds required by the Corsair drive. The only major anomaly is the application install where it requires over two minutes to complete the task, nearly twice as long as the Corsair P128.
Still, along with the terrible 4K write result, it's enough to make us worry about the V Series' long-term reliability. As for the Corsair, it delivered pretty solid real world results. But here too the 4K write results are a cause for concern. However much you pay, it seems there's no such thing as the perfect SSD.
Mid-range SSDs from £286 to £302
OCZ Vertex 120GB - £286
+ Excellent real world performance
- No major weaknesses
- The minor matter of money
One of the very first things any student of SSDs learns is that, as a species, they're a thoroughly incestuous bunch. Not only are they all much more closely related under the skin than they seem on the surface, but you also get some pretty unholy backroom rebranding going on behind the scenes.
The reason, of course, is that there are only so many companies making the two key components required for solid state drives, namely flash memory and controller chips.
If you want to create an SSD, you'll need to go and pick those parts off the shelf. Thus we come to this eerily similar looking 120GB-ish SSD pairing from memory specialists OCZ and Patriot.
Normally, these outfits are arch enemies and yet these two drives share precisely the same 2.5-inch casing. Crack them open and sure enough you're met with identical PCB layouts and virtually identical components.
Specifically, there's 128GB of Samsung manufactured NAND flash memory of the MLC variety, a 64MB SDRAM buffer and the all-important controller chip from Indilinx.
The latter is a relatively new and extremely welcome addition to the SSD ecosystem known as the 'Barefoot'.
Based on a programmable ARM processor core, it's claimed to reduce latency and increase bandwidth compared with older SSD designs based on both the ubiquitous JMicron controller and Samsung's first generation SSD controller chipset (though not necessarily the new Samsung kit as found in the Corsair and Samsung drives this month).
The upshot of all this includes some seriously juicy peak performance numbers.
Unsurprisingly, both OCZ and Patriot claim quite similar figures for maximum read performance at 250MB/s and 260MB/s respectively, the difference probably more reflecting measurement methods than any real deviation in the products themselves.
As for data write rates, both are said to top out at 180MB/s. Oh and for the record, these drives have the same capacity. OCZ prefers to go with a figure that more accurately reflects available storage after formatting.
Patriot Torox 128GB - £302
+ Huge 10 year warranty
- Catastrophic stuttering
- Poor performance across the board
Anywho, given the physical similarities you might expect them to deliver essentially the same performance. Fresh out of the box, they very probably do. However, that's not how we conducted our testing.
As you'll know from TechRadar's passim, one of the major problems with current SSDs involves long-term write performance. The root cause is derived from the way SSDs store data.
To cut a long story as short as possible, each flash memory chip is divided into 'blocks' and each block is in turn composed of 'pages'.
The specifics vary, but a typical example may be 4KB of data per page and 128 pages per block. In this scenario, a single block has a capacity of 512KB.
This matters because flash memory is read in pages and written in blocks. Of course, data doesn't always come in perfectly sized chunks, so blocks are often left only partially filled following a write cycle.
When the disk is relatively empty, unused blocks can be filled and performance does not suffer. However, as the drive fills up, data will eventually be written to partially used blocks.
When that happens, the entire block must be copied to the drive's cache memory before erasing and rewriting with a combination of the existing and new data. Needless to say, this process takes much longer than simply writing to an empty block.
Exactly how much longer depends on the elegance and efficiency of the algorithms coded into the drive's controller chip. In any case, the key issue is that drive performance drops off as the remaining blocks are filled.
However, the small size of SSDs means that in reality all available blocks will get filled quite rapidly in normal use, even if the drive is not packed with data. With that in mind, we first stuffed each SSD to the brim to ensure no blocks were left unused before formatting and installing a fresh copy of Windows 7.
Our results are therefore a guide to the performance you'll get over the lifetime of the drive as opposed to the initial out-of-the-box zippiness.
Surprisingly, they show a distinct difference between this apparently identical pairing. In fact, apart from similar peak read and write performance of around 250MB/s and 180MB/s respectively, there's a massive gulf in data throughput and it's the Patriot drive that's on the wrong end of the equation.
Our file decompression test is a typical example. The OCZ drive slices through it in just 40 seconds. The Patriot, meanwhile, requires a yawning two minutes and 56 seconds. It's also over three times slower during application installs and requires around twice as long to load a level of World in Conflict.
If that sounds bad, the subjective experience the Patriot Torqx serves up is even worse.
The drive that we tested suffered from catastrophic stutter. The stutter was bad enough to make simple things like navigating the Windows desktop a sluggish, infuriating process. Given the identical hardware and test platform, the only possible explanation for this annoying problem is firmware.
However, after flashing the drive with the latest firmware available from Patriot's website, the performance problems remain. If nothing else, the Torqx's performance problems are an object lesson in the importance of firmware.
Despite its virtually identical hardware, it's miles behind the OCZ drive with currently available firmware.
Indeed, even the Wiper.exe application created by Indilinx that supposedly removes deleted data from the memory blocks and therefore restores the performance of the drive to factory fresh levels had zero impact on the Torqx.
In the long run, it's likely that a firmware update will bring the Torqx level with OCZ's Vertex. But for now it's a pretty easy choice, especially given the latter's price advantage.
High-end SSDs from £492 to £508
Samsung PB22-J 256GB - £492
+ Excellent application performance
- Worrisome 4K random write rates
- Silly money for a hard disk
This is it, folks, the big boys of our SSD round up. Physically, of course, they're no larger than the other drives on test. In fact, thanks to its 1.8-inch form factor, Intel's X18-M is literally the smallest here.
But this final pair are collectively among the quickest and most capacious solid state drives currently available.
And they've prices to match. At £508 and £492 for Intel's and Samsung's finest respectively, you have to be hell bent on dragging your PC into the solid state era to go for either. Well, that or an investment banker pumped up with tax-payers' pounds.
Assuming you can afford the potty price of participation, just what do you receive in return for your no doubt ill-gotten gains?
Not a lot of storage capacity, that's for sure. These drives may be big by SSD standards, but they're absolutely, positively pitiful compared to the 7.5TB or thereabouts you can snag for £500 in terms of traditional spinning hard disks.
Still, what you do get is truly state-of-the-art SSD technology. After an underwhelming start with its first SSDs, Samsung is having another crack at it with a second generation drive, the PB22-J – reviewed here in range topping 256GB trim.
OK, it's based on MLC flash memory rather than the really pricey SLC stuff. But in every other regard this is undoubtedly a premium drive.
For starters, it has a huge 128MB DDR cache pool, all the better for smoothing out data transfers. Then there's the new controller chip. It's a powerful ARM-based programmable CPU and boasts eight memory address channels, double the number of Samsung's previous controller.
Needless to say, Samsung says this chip, along with the work it has done on improving the memory management algorithms in its latest firmware, results in improved performance and a reduction of the dreaded SSD stutter.
Samsung has introduced a 'self healing' feature that is claimed to clean memory blocks of residual data when the drive is idle.
All told, it's enough for extremely impressive claimed data throughput figures. Peak read performance is rated at 220MB/s and writes are barely any slower at 200MB/s.
The latter is the real killer statistic, given that write performance is arguably the biggest challenge facing SSDs today. Whether Samsung has done its homework correctly regarding the anti-stutter measures, however, we shall consider in a moment.
Intel X18-M 160GB - £508
+ Well optimised memory controller
- No longer the fastest SSD on Earth
- Poor price-per-GB ratio
As for Intel's X18-M, it's arguably even poorer value than the Samsung drive thanks to its mere 160GB capacity.
It hardly looks over endowed in the cache department either, with just 16MB. What's more, although it compares favourably with 250MB/s maximum read performance, its peak write performance of 70MB/s looks well off the pace.
But as we're increasingly realising, maximum performance figures don't always tell the whole story.
Crucially, Intel has put a lot of work into optimising for real world performance, rather than merely ensuring the X18-M looks nifty on paper. Central to that effort is an in-house controller chip design that boasts no less than 10 memory channels as well as what Intel reckons are the best wear-levelling algorithms in town and industry leading 4K random IOP rates.
If the latter sounds like digital double talk, 4K random IOPs are essentially the stuff of common disk operations, the sort of ongoing disk churn you get with normal PC usage.
Arguably, it's a better measure of real world performance than the maximum sequential read and write figures that grab so many headlines.
Finally, it's worth remembering that Intel recently released a firmware update that did much to alleviate the performance degradation issues suffered by the X18-M and X25-M drives.
Intel's SSDs may not be the newest, but they're nevertheless bang up to date. But what you really want to know is which of these solid-state data depots performs best in practice.
As with the other SSDs on test this month, we first filled both drives with data to ensure every memory block was used before formatting and installing a fresh copy of Windows. In line with the official figures, Intel takes first blood courtesy of sequential data read performance performance of 258MB/s.
Meanwhile, Samsung snags the write honours with 148MB/s, a decent figure if rather lower than the official claim of 200MB/s.
Moving to the 4K random write test, Intel's 10 channel controller and apparently superior algorithms translate into a crushing victory: 36MB/s plays 5MB/s. That's a huge margin and suggests two things:
Firstly, it looks like Samsung still has some work to do with its new SSD controller. If this is what a lightly used Samsung review drive is like, you have to worry whether its performance will hang together in the long run.
Secondly, you'd think the Intel drive should be the better bet both for the long term and for the sort of daily disk grind that's commonplace.
Somehow, however, those assumptions aren't uniformly reflected in the real world performance of these drives.
Whether it's application installation, file decompression or game level loading, the result is either too close to call or decisively in the Samsung PB22-J's favour.
That said, the 256GB Samsung seems to betray a few fleeting signs of stutters during normal usage.
However, it's a subjective impression that's difficult to capture in testing. By this stage, you may be feeling pointedly perplexed. But do not despair, you're in good company.
It's difficult to know what conclusions to draw when the test data is spitting out such mixed messages. The only cast iron advice we can give you is that SSDs remain a nascent technology prone to patchy performance.
It's simply not possible to make a purchase with complete confidence that you've chosen the best drive at any given price point, even at this rarefied end of the market.