Solid-state drives are gaining in popularity--and dropping in price. We tested a selection of them to pinpoint the ones that are perfect for your Mac.

Today’s hard disks are unrecognizable from the $3,499 5MB monster that was Apple’s first hard disk, the ProFile. And yet at heart, the basic technology is the same: a read/write head floating perilously close to delicate patterns of metal or glass, writing data magnetically on their surface. Not only is this magnetically recorded data susceptible to corruption from other magnetic devices, but the platters can also be easily damaged by rough handling.

Silent. Fast. And nearly indestructible. But are SSDs worth the cash?

SSDs (solid-state drives) store their data on a special kind of flash memory. It’s similar to what you’d find in a USB flash drive or SD card, but faster and much more resilient. Though the cost per gigabyte is still significantly higher than it is for hard disks, SSDs have many advantages. They’re fast--especially when compared to hard disks at nonsequential access--they draw less power, and because they have no moving parts, they’re both silent and much more robust.

We looked at 2.5-inch SATA drives of around 128GB; we think this is a popular, useful balance. (IDE models also exist for older, pre-SATA machines, and some manufacturers offer 3.5-inch models suitable for Mac Pros.) You can swap the hard disk from a MacBook or MacBook Pro for a solid-state drive, so if you decide to buy one, you can clone your disk to the new SSD and pop it in.

If you shop around online, you’ll notice some newer, higher-priced offerings boasting features like TRIM-command support and 6Gbps SATA III connection speeds. And you might wonder why we didn’t test any of those. Simply put, those features mean nothing to Mac users. TRIM is a command used by Windows 7 and Linux 2.6.33 to manage “garbage collection” (wiping data blocks no longer in use) and speed up performance, but Mac OS X doesn’t use the TRIM command, so that’s a nonstarter. And even Apple’s latest, greatest machines aren’t using 6Gbps SATA III connectors yet, instead topping out at 3Gbps SATA II. The drives here strike a balance between low price (well, low for SSDs) and reasonable specs for today’s Intel Macs.

The Contenders

>> Crucial M225 2.5-inch SSD 128GB $355
>> Imation 2.5-inch M-Class SATA II SSD 128GB $331.99
>> Intel X25-M Mainstream SATA SSD 160GB $434.99
>> Kingston SSDNow V-Series SATA2 2.5-inch Upgrade Kit 128GB $274.99
>> OCZ Agility Series SATA II 2.5-inch SSD 120GB $339
>> Patriot Torqx 2.5-inch SATA SSD 128GB $364
>> Transcend 2.5-inch SSD 128GB $415.99
>> Transcend Ultra 2.5-inch SSD 120GB $449.99

Did You Know?

There are two classes of SSD: MLC (multi-level cell) and SLC (single-level cell). All the drives we’ve tested here are of the slower MLC type because SLC drives tend to be both very expensive and low capacity. The usual advice is to install your OS on an SLC drive and use a second drive for data storage, but since we’re focusing on testing drives as replacements for notebook discs, fitting two drives isn’t a realistic option.

How We Tested

We decided on a testing methodology for these drives that provides megabyte-per-second data for each drive rather than timings for common tasks such as startup. Real-world timings for drives involve too many variables--such as processor speed, user reaction time, and so on--to be truly fair.

Still, we didn’t turn off the Mac-default journaling system--a file-tracking system that will slow results. And even though it will have put some drives that include DRAM caches at an unfair disadvantage, we decided to disable cache effects in our benchmarking software. We created a fresh disk image of a 10.6.2 install, then cloned it to all the SSDs. These were then fitted in turn into a 2.66GHz 15-inch MacBook Pro with a SATA II interface. We used QuickBench (speedtools.com) to benchmark performance. Each test was run 10 times. For information on the results, see the Speed Test section to the right.

We also benchmarked a MacBook Air fitted with an official Apple SSD as a reference point, as well as the 320GB hard disk that came in the test MacBook Pro. For all our results, see the benchmarks.

Value Test

Which drive will give you the best return on your cash?

Even though the market is young, SSDs are becoming commoditized; there’s very little to differentiate these drives when it comes to value. With a couple of exceptions, the price per gigabyte on all the drives here hovers around $2.75. (Since drive prices change so frequently, we’re not quoting official MSRPs from manufacturers. We think they give an artificial price point, and so the prices we quote are the best prices we can find online at press time from a reputable dealer such as Newegg or Amazon.)

The drive that offers the very best value for the money is the Kingston SSDNow V-Series Upgrade Kit. Not only is it the cheapest--both in absolute terms and in terms of price per gigabyte at only $2.15--but it also includes the most useful extras. The bundled USB disk enclosure comes in handy since Intel Macs can boot from USB drives to make the cloning process as simple as possible. It’s a terrific bundle, though if you wish, you can also buy the drive on its own.

The Transcend drives represent the poorest value. The better performing Ultra model, partly thanks to its 120GB capacity when 128GB is the norm here, costs $1.60/GB more than the drive from Kingston.

Finally, the Crucial drive scores well on value because it offers the best bang for the buck. Its performance improvement compared to a hard disk, relative to the price per gigabyte, is the highest of all the drives we tested.

Test Results

Extras Test

What else do you get in the box? And do you want it?

Because these drives all share an interface and form factor with the more popular hard disk, they don’t need anything else in the box to make them work. They’re true plug-and-play devices that don’t even require drivers.

Still, it’s always nice to get extras, and some manufacturers put other bits in the box to try to entice us. Sadly, while many of the drives here include software to help you clone your hard disk to your new SSD, none works on the Mac. It’s no great loss, however; savvy Mac users will already be familiar with excellent tools such as SuperDuper (shirt-pocket.com) and Carbon Copy Cloner (bombich.com) that will do the job easily. Both are free, too, though of course you can pay to unlock more features or make a donation, respectively.

Three drives do offer some extras that are potentially useful, however. The least appealing comes with the Patriot Torqx; it includes a bracket to let the drive be mounted in the 3.5-inch slot of a desktop computer, but sadly the screw holes for mounting the adapted drive are on the sides, which is useless for Mac Pro owners whose drives are attached by screwing them vertically to drive caddies.

Imation’s offering is better: It’s a SATA-to-USB interface that lets you connect your SSD to your Mac to let you clone from one drive to the other.

Kingston impressed us the most, though. Included in the box was an easy-to-open case for a 2.5-inch SATA drive that connects over USB. Once you’ve cloned your drive across, you can simply pop your old hard disk in this case and keep it around as a handy external USB drive.

Test Results

Speed Test

All these drives are faster than a hard disk--but how much faster?

Storage performance varies depending on whether files are being read or written, whether the files are small or large, and whether the data is being written randomly or in one sequential chunk. In the latter case, random reads/writes are usually a more realistic indication of performance, given that it’s rare that large files are able to be written in a single go.

We used QuickBench to test all these variables. Results are shown on the next two pages. The results were sufficiently similar for file sizes between 2 and 10MB, and between 20 and 100MB, for us to report only the average for reads and writes across these file sizes. These results represent what most of us would think of as a disk’s speed--this is what we’re exposed to when we save or copy a file.

Still, it’s the smaller file sizes that provide more interesting, divisive information. These smaller chunks, which we’ve reported in their entirety, are more indicative of the kind of performance you’re likely to be affected by minute by minute, representing as they do the kind of tiny packets of data the operating system is shunting around as it’s working away.

Slow speeds here will make your system feel sluggish, though if you have oodles of RAM and a fast Mac, the effects will be less obvious. And if you have a setup like this, you’re likely working with large media files, and so will be more concerned with the load/save times of large chunks of files. If this is you, check the large and extended results.

The first thing to note is that all the SSDs trounced the hard disk, especially--as we’d expect--when it came to the random reading and writing of small blocks of data.

The clear loser here was the Kingston drive. Although its performance usually matched that of the official Apple SSD in the MacBook Air, it was often significantly slower than the other drives. And while the drive from Intel performed well when reading, its write speeds for large chunks were consistently disappointing.

The drives from Crucial, OCZ, and Patriot, and specifically the Transcend Ultra, all performed well, and there’s little to differentiate their performance. On average, the Patriot drive just squeaks ahead.

Test Results

Next Page: Benchmark Graphs >>