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Seagate's Barracuda 7200.9 hard drives

Big drives, dense platters

ModelBarracuda 7200.9
Price (500GB)


IN THE HARD DRIVE WORLD, capacity is king. Capacity actually comes in two flavors. The first and most obvious is the storage capacity of a hard drive. The second, and potentially more important, is the capacity of individual platters within a drive. This platter capacity is known as the areal density, and it can do more than just increase the amount of data a drive can hold. Higher areal densities allow drives to offer more storage capacity with fewer platters, potentially lowering noise levels, cutting power consumption, and reducing the risk of a catastrophic head crash. As if that weren't enough, higher areal densities can also improve performance by allowing the drive head to access the same amount of data over a shorter physical distance.

Seagate's new Barracuda 7200.9 family of Serial ATA hard drives packs storage capacity on both fronts, with one model weighing in at a hefty half-terabyte and another packing a single 160GB platter whose areal density is 25% higher than its closest competitor. We've rounded up both models and run them through a brutal gauntlet of storage tests against earlier Barracudas and drives from Hitachi, Maxtor, and Western Digital. Read on to see how the 7200.9s compare.

Drive specs
Although the Serial ATA Revision 2.5 spec has yet to be ratified by the Serial ATA International Organization (SATA-IO), all of the draft spec's standard and optional features are implemented across the Barracuda 7200.9 line. Those features include, but are not limited to, provisions for staggered spin-up, hot plugging, auto-negotiated backwards compatibility, ClickConnect connectors, and (most importantly) Native Command Queuing (NCQ) and 300MB/s host transfer rates.

  Barracuda 7200.9 Barracuda 7200.8
Maximum external transfer rate300MB/s150MB/s
Average seek time11ms
Average rotational latency4.16ms
Spindle speed7,200-RPM
Available capacities80, 120, 160, 200, 250, 300, 400, 500GB200, 250, 300, 400GB
Cache size8MB (80-250GB)
16MB (300-500GB)
Platter size100GB (200, 300GB)
120GB (120GB)
125GB (250, 500GB)
133GB (400GB)
160GB (80, 160GB)
Idle acoustics2.5-2.8 bels2.8 bels
Idle power consumption6.9W7.2W
Seek  power consumption8.1W12.4W
Service lifeFive years
Warranty lengthFive years

300MB/s Serial ATA transfer rates are all the rage, but not even the fastest 15K-RPM SCSI drives can sustain transfer rates that saturate a 150MB/s Serial ATA interface, giving 7,200-RPM drives little hope of benefiting from anything faster. However, 300MB/s host transfer rates can allow for faster burst transfers from a hard drive's cache. With drive cache sizes growing, it may be unwise to write off 300MB/s Serial ATA transfer rates as a gimmick just yet.

Speaking of cache, drives in the 7200.9 family are equipped with either 8MB or 16MB, depending on their capacities. Higher capacity drives get more cache, with the 300GB, 400GB, and 500GB models packing 16MB each.

The 7200.9 line is also segmented when it comes to platter density. There are quite a few variations, with five different platters spanning eight drive capacities. Today we'll be focusing our attention on the 500GB and 160GB capacities, which feature 125GB and 160GB platters, respectively. 125GB platters are hardly unique in the hard drive world, but they allow Seagate to build a 500GB drive with only four platters. The only other 500GB drive on the market, Hitachi's 7K500, uses five 100GB platters to reach the half-terabyte mark.

The Barracuda 7200.9 500GB (left) and 160GB (right)

While 125GB platters aren't all that special, no one can match Seagate's ultra-dense 160GB platters. Only Seagate's own 133GB platters come close, and even then, the 160GB platters offer a 25% jump in areal density. That allows the 160GB Barracuda 7200.9 to be built using just a single platter, with all of the attendant advantages of fewer platters. The 160GB model's denser platter should also provide a nice performance boost. You won't find 160GB platters in drives larger than 160GB, though, and these platters aren't available in drives with more than 8MB of cache, either.

Fortunately, all members of the Barracuda 7200.9 family are covered by Seagate's fantastic five-year warranty. This longer warranty term is usually reserved for SCSI drives and enterprise-class products, while desktop hard drives from other manufacturers are generally only covered for three years. Seagate, however, warrants its entire internal hard drive line for five years.

Barracudas over easy