Seagate Barracuda Green 2 TB Hard Disk Drive Review
By Gabriel Torres on May 27, 2011
The Barracuda Green 2 TB is Seagate’s first hard drive to use 4 KB sectors instead of 512-byte sectors. The new standard, also known as “Advanced Format” or simply “AF,” will be used by all hard drive manufacturers in the future. Let’s see what are this new format and the performance of the Barracuda Green 2 TB drive.
The hard disk drive magnetic platters are divided into sectors. Each sector has an area before (addressing information) and after (error correction code, a.k.a. ECC) the data area to store control information. These areas occupy space on the platter, but this space is not available to the user. By expanding the size of the physical sectors on the hard drive platter, fewer areas for control purposes are necessary, leaving more area available to the user.
In the new Advanced Format, sectors can store 4 KB of user information, so one 4 KB sector stores as much as eight 512-byte sectors. This means that instead of having eight pairs of control areas, the new 4 KB sector has only one pair. The seven pairs of control areas that were freed by each 4 KB sector can now be used to create more sectors on the disk. See Figure 1 to understand. Therefore, a platter using 4 KB sectors can have more sectors than if the same platter were using 512-byte sectors. In summary, the Advanced Format allows the same platter to hold more user data, i.e., have greater capacity.
Ideally, the hard drive must have a translation mechanism to improve performance when the hard drive receives write commands based on standard 512-byte sectors from the computer. If not, the drive will have to read the entire 4 KB sector, update the 512-byte portion that was sent by the computer, and then write the entire 4 KB sector back on the drive. This situation, called “read-modify-write,” degrades performance a lot; according to Seagate, this performance drop can be as high as 40%. In the Barracuda Green 2 TB, Seagate added a translation mechanism called “SmartAlign technology” to address this issue.
More information on the new Advanced Format can be found here.
The Barracuda Green 2 TB, as you can infer by its name, belongs to the “Green” hard drive family from Seagate, formerly known as the Barracuda LP. All major hard drive manufacturers have a “green” product line, with drives spinning at a lower speed in order to save energy. The Barracuda Green 2 TB spins at 5,900 rpm, while regular desktop drives spin at 7,200 rpm. Therefore, the drawback of saving energy is a possible drop in performance. On the other hand, the Barracuda Green 2 TB uses the SATA-600 interface, while most other “green” hard drives are still based on the old SATA-300 standard.
In the table below, you can see the drives we included in our comparison. We included a standard desktop model based on the SATA-600 interface, the Barracuda XT, and the old Barracuda LP, which is based on the SATA-300 interface and doesn’t feature the Advanced Format technology.
All prices were researched at Newegg.com on the day we published this review. The Barracuda LP 2 TB isn’t sold anymore.
During our tests we used the configuration listed below, and the only variable component between each benchmarking session was the hard drive being tested.
We adopted a 3% error margin, so performance differences below 3% cannot be considered meaningful. In other words, products where the performance difference is below 3% must be considered as having similar performance.
HD Tune provides four results. The burst transfer rate (which is the maximum transfer rate achieved between the hard disk drive controller located on the hard drive printed circuit board and the SATA-600 port on the motherboard), the minimum transfer rate, the maximum transfer rate, and the average transfer rate. Let’s analyze the results.
On the burst transfer rate test, the Barracuda Green 2 TB achieved a performance 8% higher than the Barracuda XT 2 TB and 36% higher than the Barracuda LP 2 TB.
On the average transfer rate as measured by HD Tune, the Barracuda XT 2 TB was only marginally faster than the Barracuda Green 2 TB (4%). The Barracuda Green 2 TB was 15% faster than the Barracuda LP 2 TB.
On the maximum transfer rate as measured by HD Tach, the Barracuda Green 2 TB and the Barracuda XT 2 TB achieved the same performance level, with the reviewed drive being 15% faster than the Barracuda LP 2 TB.
On the minimum transfer rate test, the Barracuda Green 2 TB was 11% faster than the Barracuda XT 2 TB and 29% faster than the Barracuda LP 2 TB.
Let’s now see the results provided by HDTach. This program gives us two results: the burst transfer rate and the average transfer rate.
On the burst transfer rate test, the Barracuda Green 2 TB achieved a performance 12% higher than the Barracuda XT 2 TB and 49% higher than the Barracuda LP 2 TB.
On the average transfer rate as measured by HDTach, the Barracuda XT 2 TB was only marginally faster than the Barracuda Green 2 TB (4%). The Barracuda Green 2 TB was 15% faster than the Barracuda LP 2 TB.
Access time is another important measurement. It measures the time the storage device delays to start delivering data after the computer has asked for a given data. It is measured in the order of milliseconds (ms, which are equal to 0.001 s); the lower this value, the better.
The Barracuda Green 2 TB achieved the same results as the Barracuda XT 2 TB.
We were really impressed by the Barracuda Green 2 TB. It achieved practically the same performance level of the Barracuda XT 2 TB, while costing half as much. Also, it was 15% faster than its predecessor, the Barracuda LP 2 TB. Seagate is definitely on the right track with its implementation of the new Advanced Format using its own translation mechanism. If you are looking for a 2 TB hard drive at an incredible price (only USD 80) and good performance, the Seagate Barracuda Green 2 TB is the way to go.