Sony’s Advanced Intelligent Tape (AIT) format is 10 years old, during which time the company has doubled drive capacity every two years and continually improved performance to keep pace with developments in disk technology.

So much so that the latest AIT-5 drive can cram a whopping 400GB of uncompressed data onto each tiny AIT cartridge, at a sustained transfer rate of 24Mbytes/sec. Despite its big memory, it’s still small enough to fit into a half-height drive bay the likes of which are found on most small business servers.

We tested the bare internal AIT-5 drive, designed to be sold and installed by server vendors and system integrators. However, an end-user Storstation bundle is also available, complete with mounting rails for use in HP Proliant systems and a copy of Symantec’s Backup Exec 10d for Windows Servers software. An external Storstation model is also available and both are covered by a three-year rapid replacement warranty.

The AIT-5 drive is also set to be added to Sony’s range of tape automation products later this year.

New badge apart, the SDX-1100 drive itself looks similar to its predecessors. It’s front loading, can be bought in black or white and comes with enough ironmongery to fit the drive into either a 5.25in or 3.5in half-height slot.

Installation is, naturally, a screwdriver job, but it only took a few minutes. The Ultra160 SCSI LVD/SE interface, however, is unchanged from the AIT-4 which, although plenty fast enough, meant having to fit a plug-in adapter on the Sata-equipped server we used for our tests. But then, that’s not a big problem and if required shouldn’t add significantly to the price or installation time.

On the performance front the transfer rate figure of 24Mbytes/sec native is impressive, but isn’t much faster than with AIT-4. Likewise you need to take with a pinch of salt the 2.6:1 compression ratio claimed for Sony’s ALDC (Adaptive Lossless Data Compression) technology which, if it were to be achieved, would significantly boost both capacity and throughput.

Unfortunately a lot of data will already be compressed and using typical datasets of moderately compressible documents, we saw improvements of about 40 per cent. Good, but nowhere near as good as claimed.

In its favour the AIT-5 drive will be able to fit the contents of most small-business servers onto a single cartridge. It can also read and write to cartridges designed for use in AIT-3, AIT-3EX and AIT-4 products with Worm (Write Once Read Many) cartridges also available for long-term data archiving.

All of which is good news for existing AIT users who will only have to splash out on the new AME III (Advanced Metal Evaporated) tape cartridges to get the full benefit of the extra capacity. We found AIT-5 cartridges being offered online for just £40 ex Vat, which works out at a very affordable 10p per gigabyte.

Unfortunately the drive itself is far from cheap. Indeed, it could more than double the cost of a small-business server. If cost is an issue, therefore, we recommend alternative disk-based backup solutions that can match or exceed the capacity and throughput of tape drives for a lot less.

However, for backup to removable media, tape is hard to beat and AIT compares well on price against competitive formats, few of which can match the latest AIT-5 implementation on capacity, performance or its diminutive size.