High-capacity USB flash drives

Verdict: Get up to 64GB of hardy flash memory in your pocket.

While portable hard drives that use 2.5in laptop disks offer large capacities, they're relatively fragile. The latest USB flash drives have reasonably large capacities for reasonable prices, so we've put seven of the largest we could find to the test to see which are worthy of your cash.

How we tested

Our tests involved reading and writing various files to and from each drive. These included single 3GB and 700MB video files, as well as a 740MB folder containing 5,580 individual small files ranging from Word and Excel documents to image files. This test is a good indicator of how well a drive can cope with transferring large photo or document archives. We also played the 3GB DVD-quality video file from the slowest drive to find out if it could provide smooth playback, or if you'd have to copy the file to your PC and play it from there.

Results

All the drives on test were fairly slow compared with a hard disk, but the Corsair Flash Voyager 64GB took the biscuit. It costs a whopping £147.45 and took more than 20 minutes to write the 740MB folder of small files - that's a write speed of just 0.5MB/sec. Copying gigabytes of documents or photos will take a very long time. It also performed averagely in the medium- and large-file copying tests, with write speeds in particular well below par. It has the highest capacity of the drives on test but you'll go grey before it writes 64GB of data. If you need more than 50GB of portable storage, you'd be better off with an external 2.5in drive.

With the storage section screwing into a rugged cylinder sealed by a rubber o-ring, Corsair's Flash Survivor 32GB might fare well if it fell out of a sailor's pocket but it wasn't too clever at transferring files. In fact, it was the second slowest drive on test and costs much more than either of the other 32GB USB flash drives on test. Like the Corsair Flash Voyager 64GB, it took more than 20 minutes to transfer the 740MB folder of small files, with a write speed of just 0.6MB/sec. Its read and write speeds when copying the large video files were also poor. The Flash Survivor is only worth considering if you're worried about your data device being destroyed.

The Lexar JumpDrive Secure II Plus 16GB has an LCD that shows how much storage is left on the drive, and costs twice as much as other 16GB drives on test at £46.99. It was slow at copying video files though. Write speeds were 8.3MB/sec, while read speeds were the slowest on test at 18.9MB/sec. However, playback of the 3GB DVD-quality video file was smooth, proving that you can load any of the flash drives on test with a library of films to share with friends or play on a laptop. The JumpDrive was slow at reading the 740MB folder of small files, but managed to write the same data very quickly at 1.8MB/sec.

The PNY 16GB Attache Optima is the second cheapest drive on test, retailing for £29.26. The storage drive slides out and swivels from a protective frame, although we have doubts about the strength and High-capacity USB flash drives longevity of this mechanism. It also makes the drive cumbersome to use. The PNY performed well in all the tests, however, maintaining read speeds of 24.6MB/sec and write speeds above 13.3MB/sec in the large file transfer tests. While it was relatively quick at dealing with the 740MB folder of small files, none of the USB flash drives was particularly fast.

The Freecom DataBar 16GB is even better value at £22.85 for 16GB of storage. It delivered mixed results in our tests, however. The Freecom had the slowest write speeds of any drive when transferring the large and medium files, bottoming out at just 6.5MB/sec. In contrast, it performed much better when reading, recording the fastest read speed of all the drives at 29.4MB/sec for the medium-sized file. The Freecom's performance was average when reading and writing the 740MB of small files.

The worst feature of the Kingston DataTraveller 150 32GB is its vomit-coloured exterior. The drive has 32GB of capacity and was one of the fastest drives on test, almost reaching 30MB/sec in the video transfer tests. The write speed of 17.6MB/sec for the 3GB video file was the fastest of all the drives. The Kingston coped fairly well with the 740MB folder of small files, with speeds comparable to those of the fastest drives on test.

The OCZ ATV 32GB was also quick at writing the 3GB video file, and recorded the fastest write speed of any drive when dealing with the medium-sized 700MB video file, with an average transfer rate of 16.8MB/sec. The OCZ was streets ahead of the competition when writing the 740MB folder of small files, managing an average write speed of 2.3MB/sec. Considering that it has a cap holder on the chain, is waterproof, looks cool and costs only £60, it's the best choice. If you're looking to save cash, the PNY or Freecom 16GB drives are worth a look.

As the OCZ was the fastest drive on test, we tried to install Windows XP on it to determine if you could make it into an SSD on the cheap. However, the installation took a full day and the drive returned BSODs every time we tried to boot from it.