Storing your video files and images – not to mention your iTunes library – demands masses of hard drive space. Here’s how to beef up your storage space.

The volume of data the creative professional hoards nowadays means that storage is an increasing problem. Video files, photos, and an ever expanding MP3 collection means even home computer users are seeing their hard drives fill up.

Fortunately, it's a fine time to add a massive new hard drive to your system. The average price per gigabyte is at an all-time low. You may want to swap out your old drive for a new 400GB behemoth, or make your existing drive part of a two-drive RAID configuration for better speed.

SATA-iated

SATA hard drives arrived on the scene about two years ago, but they're becoming the mainstream drive of choice only now. The lag was expected – since most motherboards supported only the Parallel ATA interface at the time SATA drives debuted, early SATA adopters had to buy PCI adaptor cards. Today, however, most new motherboards offer integrated SATA connections (as well as legacy PATA connectors), and market research firm IDC expects SATA drive shipments to outstrip PATA by mid-2005.

SATA's refined design represents a step up. PATA ribbon cables are wide and impede air flow, whereas SATA cables are easier to attach and significantly less bulky. SATA drives are simpler to connect and configure, too, with no master/slave jumpers to set. And finally, SATA offers greater bandwidth. Its maximum transfer rate of 150MBps is an improvement on PATA's maximum rate of 133MBps.

The transfer-rate headroom may not translate into extraordinary performance gains in single-drive systems, but it can pay off in multidrive and RAID setups in which several drives access the data bus simultaneously.

After SATA

Drive vendors are already looking beyond the original SATA specification. The next evolution of SATA doubles SATA's peak transfer rate to 300MBps. Another new feature is native command queuing (NCQ), which enables a drive to store and execute commands independently in the most efficient order possible.

Under testing, SATA drives did better than their PATA rivals. On average, the SATA group copied files and folders in 17 per cent less time than the PATA drives, and copied a single 3GB file in 20 per cent less time. You may not see the same gains with a different configuration or an older PC, but the improved cabling can still help your system's airflow. And it will be easier to transfer the drive you get today to the next PC you buy.

Other buying criteria include capacity, price, rotational speed, and buffer size. Capacity needs are very user-dependent; but graphics, music, and video users should go for the biggest size they can afford, since media files eat up hard-drive real estate in a hurry.

The great majority of mainstream hard drives spin their platters at 7200rpm. You should avoid the increasingly rare 5400rpm drives if performance is a primary consideration. Only one manufacturer – Western Digital – today makes a 10,000rpm ATA drive. The company's 74GB Raptor WD740GD uses the SATA interface – it was designed for use in enterprise RAID configurations. It's no slouch in a desktop RAID 0 setup, either.

When we paired Raptors in a RAID configuration, we got outstanding performance, even though the Raptor lagged slightly behind the average SATA drive in some of our single-drive tests. Because of its relatively small capacity and high performance in arrays, the Raptor is often configured in RAID arrangements in high-end desktops and servers. Gamers and video editors, in particular, can benefit from this type of setup.

Though buffer size is a basic drive spec, assessing the merits of different buffer sizes is difficult. Any correlation between buffer size and improved speed is sketchy at best: In our tests, in both the PATA and the SATA categories, the fastest drives used 8MB buffers, while several runners-up employed 16MB buffers.

Pass the screwdriver

One difference we observed among the drives: The SATA connectors on Western Digital's SATA drives are noticeably bigger and sturdier than those on competing models. While still meeting the SATA standard, the connectors are a bit wider and have two additional male/female friction points on the outside for more-secure fastening. Also, Seagate includes backup software with its drives: CMS's useful (though inelegant) BounceBack Express.

Big, speedy drives

For this roundup we corralled six PATA drives: two versions (200GB and 250GB) of Maxtor's DiamondMax 10, Samsung's 160GB SP1604N, two Seagate Barracuda 7200.8 models (250GB and 400GB), and Western Digital's 250GB Caviar SE WD2500JB.

On the SATA side, we tested Hitachi Global Storage's 250GB Deskstar 7K250 and 400GB Deskstar 7K400, Maxtor's 250GB and 300GB, DiamondMax 10 units, Seagate's 400GB Barracuda 7200.8, and Western Digital's 74GB Raptor WD740GD and 250GB Caviar SE WD2500JD. The WD740GD is a 10,000rpm drive; all of the others spin at 7200rpm.

In our benchmark configuration for single drives, the SATA models tended to be impressive performers. In our time trials for transferring 3GB of files and folders, top honours went to Seagate's 400GB Barracuda 7200.8. Maxtor's 250GB and 300GB DiamondMax 10 models were runners-up, just over 20 seconds (about 12 per cent) off the pace set by the Barracuda.

In fourth, a few seconds behind the Maxtor drives, was Western Digital's 250GB Caviar SE WD2500JD, followed by Hitachi's 250GB Deskstar 7K250, Western Digital's Raptor WD740GD, and Hitachi's 400GB Deskstar 7K400.

In the PATA ranks, Western Digital's Caviar SE WD2500JB led the pack on our file-and-folder test, followed closely by Seagate's 400GB and 250GB Barracuda drives. A greater gap separated the Caviar SE from the fourth- and fifth-place finishers: Maxtor's 250GB and 200GB DiamondMax 10 drives. Samsung's SP1604N, which finished dead last in performance and missed our chart, trailed the number one Seagate Barracuda by 20 per cent.

Given how close our test results were, all of these drives are easy to endorse. That said, we advise you to get SATA – even if that entails buying an affordable PCI controller card. Select a high-capacity, money-is-no-object SATA drive (like our chart topper, Seagate's 400GB Barracuda), or balance price and capacity with Maxtor's DiamondMax 10 6B300S0. For optimum desktop performance, a RAID 0 array with multiple Western Digital Raptor WD740GD drives is a sure but pricey bet.

Hard drives gain racing stripes

RAID (Redundant Array of Independent Disks) comes in a variety of flavours. The one that is most commonly used with desktop systems, RAID Level 0, isn't really a type of RAID at all (thus, RAID "0") because it doesn't provide any redundancy.

RAID 0 stripes (or parcels out) data across multiple drives to create one larger logical drive, delivering much faster sustained reads and writes along with sometimes slightly slower random access.

Another advantage of RAID 0 is relatively low cost. Drive vendors charge a hefty premium for their largest models, so you can achieve a better cost per gigabyte by combining multiple smaller-capacity drives.

Most mainstream add-in RAID cards and motherboards also support RAID Level 1 (mirroring), which writes the same data to two drives at once for data redundancy in case one of the drives fails. In addition, some cards let you combine RAID 0 and RAID 1 (RAID 0+1) so you can mirror a pair of striped drives (if you have four drives).

The Raptor WD740GD posted the fastest or the second-fastest time on every RAID 0 test. Its biggest gains came on our large-file and file-and-folder tests, with jumps of 32 per cent and 43 per cent over a stand-alone Raptor. This RAID setup also outperformed the average single SATA drive in some – but not all – of our tests.

You don't have to graduate to a 10,000rpm drive to see performance improvements with RAID, though. When configured using RAID 0, Western Digital's SATA Caviar SE WD2500JD improved its times by 26 per cent and 33 per cent, respectively, on our large-file and file-and-folder tests.

Given the sizable boosts we saw in our tests, we'd recommend a RAID setup to anyone seeking optimum PC performance. Just be sure to back up regularly: The big disadvantage of RAID 0 is that if one drive goes bad, you lose the data on both.