Verdict: Hard disks take a perpendicular turn
Who doesn't like a big number? Even the world's most well-known website is named after one of the largest ever imagined. Processor manufacturers have moved away from their gigahertz obsessions, but one area of computing is still very much in love with all things numerically massive - storage.
The latest hard disk to break all records for being gigantic is Seagate's new Barracuda 7200.10, the tenth generation of this illustrious range. Whereas the previous pinnacle of platter prowess was 500GB in a 3.5in case, the top member of the 7200.10 range smashes past this to store 750GB in the same amount of space. The new Barracuda achieves this quantum leap by being the first desktop drive to use a new technology called perpendicular recording. Until now, the tiny magnetic grains that store information on a hard disk's platter have been arranged lengthwise along the surface - or longitudinally, to give this its proper name. With perpendicular recording, as the word suggests, the magnetic grains are arranged at a right angle to the surface of the platter. Since the grains are longer than they are wide, you can fit more of them in a given space compared with longitudinal recording.
The reason that hard disks need to go perpendicular is the rather grandly named 'superparamagnetic effect'. This is the somewhat mythical point at which magnetic grains become so small that a mere change in ambient temperature would be enough to flip them and thus ruin the data. Hard disk manufacturers have been living in fear of the superparamagnetic effect for years, as this theoretically limits areal density to between 100 and 200Gb per square inch of platter using conventional longitudinal recording. Current hard disks already reach this level. However, perpendicular recording has now been demonstrated well above 200Gb per square inch by both Hitachi and Seagate, and is expected to be capable of 500Gb per square inch. This would allow 3.5in hard disks to reach as much as 2TB capacity.
Toshiba and Hitachi have released 2.5in perpendicular laptop products, but so far, Seagate is the only manufacturer to offer desktop perpendicular drives as well. The Barracuda 7200.10 gets its 750GB by bringing together four platters, each with 187.5GB of storage space, making it the current market leader in areal density. The 750GB model has the highest areal density, while the lesser members of the 7200.10 range sport 160-170GB per platter. The capacity is partnered with 16MB of cache and a S-ATA II interface supporting NCQ (Native Command Queuing).
Although the 7,200rpm spindle rate can't compare with Western Digital's 10,000rpm Raptor X, with such a huge areal density we were expecting stunning performance from the 7200.10. The Seagate was certainly no slouch in our synthetic HD Tach 3 RW tests. The average read and write throughputs of 66.5MB/sec and 58.3MB/sec respectively were faster than those of any drive we've seen, bar the Western Digital Raptor X. However, the 13.8ms access time was merely par for the course for a 7,200rpm drive.
In our real-world tests, we remained impressed. It's worth noting that the motherboard in our test rig has changed from the seminal Asus A8N-SLI to an ASRock 939Dual-SATA2, so we ran our 2D benchmarks on this rig's resident 80GB Hitachi Deskstar 7K250 for comparison, garnering a score of 1.35. Compared to this, the Seagate's 1.49 looks particularly capable. The Far Cry level load of just 50 seconds is the fastest we've seen, but this result will be primarily due to Far Cry being installed on the fastest outer portion of the platters. As with most hard disks, the inner portion is around half as quick, so performance will drop as the drive fills.
CONCLUSION
Big drives normally have big price tags but, once again, the Barracuda 7200.10 bucks the trend; it isn't a tremendous bargain, as you'd still be able to purchase a trio of 250GB Barracuda 7200.9s for less, but, at 35p per gigabyte, it's better value than any other current 500GB disk. The 750GB Barracuda 7200.10 has all the big numbers covered, for a price that isn't as ludicrous as you'd expect.
