And in this corner… The hard drive Storage Wars have been heating up lately as Western Digital and Seagate battle it out for not only the largest capacity disks, but they are also going green! Western Digital went as far as to name it’s new 2TB hard drive the Caviar Green series. Before I get into how 2TB hard drives work and why buyers should beware, let’s look at how a hard drive can be green. Western Digital has slowed the RPM’s down to 5400 on their Caviar Green, hoping to reduce heat and power consumption, without users noticing the drastic drop in speed. While Western Digital is by far the leader in high capacity storage for consumers, Seagate is also dipping their feet in by offering their 2tb drive as SATA, not just SAS. For those of you unsure about SAS and SAS 2.0, it is meant for enterprise level storage needs, not Joe Public. Western Digital has their 2TB hard drives going out as OEM as well as offering the drive in their online store. They also have a 2 hard drive 2TB My Book out that offers protection in the form of a RAID 1 mirror.
The 2tb My Book is priced to sell with a tag under $300.00. In fact it is really a two drives for the price of one situation since the OEM Caviar Green is $280.00 for just one hard drive. This is kind of confusing since I don’t see how they can sell 2 hard drives for the cost of a single internal 2tb drive. If you add up the speed slow down of 5,400 RPM along with its USB interface, this drive is OK for backup, but just won’t cut it for users planning to actively store and watch movies or listen to music.
Why 2TB Hard Drives Scare IT Professionals
Both Western Digital and Seagate have released 2TB hard drives this year. Even though the physical size of the drives remain at 3.5 inches, they are holding quite a bit more data. How did they pull that off? A couple of years back, Toshiba released information about perpendicular recording as a new technology for traditional magnetic storage, but it was Seagate that delivered the first drive to consumers.
Perpendicular recording significantly increases the areal density and storage capacity of hard drives. The ones and zeroes are now stored vertically rather than horizontally. This allows for much greater storage because a sector can hold the same amount of data, but in a much smaller sector size. For example, if a platter can hold 100 sectors with longitudinal recording it will be able to hold 250 sectors with perpendicular recording. Using this technology and other advancements, hard drive manufacturers can now have areal density up to 500GB per platter. A 2TB hard drive will have four platters that hold 500GB each.
The problem here is that this type of areal density squeezes more and more bytes into sectors making them smaller and smaller. The heads have to be perfectly aligned to read and write to the sectors correctly, and more importantly read and write to those sectors on a consistent basis. If the heads write to the sectors even a hair out of alignment, then that data will be corrupt. If this happens over and over again, soon the OS won’t load and the computer won’t boot. If that doesn’t sound bad enough, the level of heat the motor generates to spin 4 platters, will swell the platters and the same problem happens – the sectors get out of whack and data gets corrupt. There is an old Latin phrase Caveat Emptor that means “buyer beware”. I bring this up not to criticize Western Digital and Seagate or their ability to make hard drives, but to warn our readers about high capacity hard drives and to ask you all to take a wait and see attitude beofre plunging in and getting another drive because it is new. As owners of Seagate’s 7200-11 series drives found out to their misfortune, new technology often needs to be tested thoroughly before being released en-masse! If you do take the plunge and go for a 2TB hard drive, you better get 2 and use them to back each other up. If you have a 2TB disk failure you will need hard drive recovery so back up!