- THREE TERABYTES!
- Low power draw (for an HDD)
- Support for XP is iffy
- Requires a few extra hoops
The Western Digital Caviar Green 3TB is nothing less than a standard for other manufacturers to follow as they bridge the 2.19TB gap.
Today, Western Digital made waves with the introduction of their new Caviar Green 3TB hard drive. Western Digital may not be the first to announce or release a 3TB drive, but they’re certainly the first to make it available as a standalone unit. Breaking the 2TB barrier poses substantial problems for both companies and end users – has Western Digital managed to make the upgrade a painless process?
- Capacity: 3.0TB (3000GB)
- Spindle speed: unpublished, but somewhere between 5400 and 7200 RPM (WD IntelliPower)
- Cache: 64MB
- Platters: 4 x 750MB (for the 3TB model)
- Host interface: SATA (3Gbps)
- Acoustics: 24dB – 25dB
- Rated power consumption: 10.75W at startup, 5.5W idle, 6.25W read/write, 1W standby/sleep
The MSRP for Western Digital’s new Caviar Green 3TB hard drive is $239.99; a smaller 2.5TB version will retail for $189.99.G
The 2.19TB barrier
As mentioned, Western Digital wasn’t the first storage company to release a 3TB drive; competitor Seagate beat them to the punch with their external 3TB GoFlex drive back in June. WD released their own 3TB external drive a little over three months later. Why were they only available as external drives for so long? The 2.19TB barrier.
The 2.19TB barrier is a result of the way most computers have, until recently, handled storage addressing. Thanks to older BIOS software and legacy drive partitioning, going past this limitation is a complicated process. Older systems rely on MBR-style drive partitioning, created in the early nineties. This standard uses 32-bit values to describe a drive’s partition parameters.
Because of that 32-bit limit, drives are limited to roughly 2.19TB and can contain only four primary partitions. A new solution was devised by the UEFI forum known as GPT, or the GUID Partition Table partitioning scheme.
For our purposes, GPT uses 64-bit addressing to delineate partition parameters which means that it can support much, much larger storage arrays. In this case, while MBR partitioning can support up to 2.19TB, GPT partitioning can support up to 9.4ZB, or zettabytes. That’s over 4.29 x 10^9 times as much data. We’d never be so foolish as to assume that that will always be enough, but…it should last a while.
As part of the requirement for GPT partitioning, Western Digital’s 3TB Caviar Green drive requires, essentially, a 64-bit operating system (at least, it does if users wish to boot from the drive – 32-bit versions of Windows Vista and Windows 7 are supported, but only as a dedicated data drive. On top of the 64-bit operating system requirements, only motherboards that support UEFI can coerce the new drive into pulling primary boot duties.
Currently, Western Digital says that Linux is supported, although ensuring compatibility is ultimately left up to the Linux end user. Apple’s recent iterations of its OS X operating system are also supported, but only within the OS; Boot Camp can’t be used.
In addition to the incompatibilities posed by the above scenarios, Western Digital foresees there being a number of issues raised by complications with certain chipsets (namely, Intel and Nvidia) and system BIOSes. To get around this, WD is packing a 3rd-party HBA, or host bus adapter along with every shipping 2.5 or 3TB drive.
Our drive came with a HighPoint Technologies Rocket 62x PCI-e to 2 x SATA HBA card, and though Western Digital didn’t say that every drive would receive the same HBA, it seems a likely bet. The point behind the additional card is that (mostly for Windows) the card comes with a set of known drivers that work, and work well. WD can ship drive + HBA and not have to worry whether the end user will have to deal with driver conflicts.
According to the company, driver updates for both Intel and Nvidia chipsets should be forthcoming in the first half of next year – once these are widely available, the HBA will no longer be packaged along with the 2.5 and 3TB drives.
Build and design
While the drive looks much the same as the last generation of Western Digital’s Caviar Green lineup, the internals are decidedly different. The 2TB Caviar Green drive used 3 platters each comprised of 667GB, while the 3TB Caviar Green drive uses fully four platters, each storing 750GB. This is in contrast to Seagate’s 3TB Barracuda XT, which currently uses 5 platters of 600GB each.
The upside to using fewer platters is that the drive uses less power, makes less noise and is subject to fewer failures – after all, it uses less noise. Ideally, using greater density platters should also mean that the drive is faster, since the heads move over more information with each spin of the wheel.
As drive manufacturers realize greater and greater storage densities, the need to move past the fifty-year old 512 byte sector format has grown and grown. For years, companies like WD have been able to change how the hard drive’s sectors are formatted – the problem is that it introduces significant compatibility problems with pre-existing devices.
The compromise was essentially to introduce a hack – at least, for the time being. New drives, such as the 3TB Caviar Green, actually use 4,096 byte, or 4K, sector formatting – that is, data is stored on the hard drive in groups of 4,096 bytes. 4K formatting would ordinarily introduce those compatibility issues, so while the drive is physically formatted using 4K sectors, the rest of the computer sees it through a veil of 512 byte emulation. Known as 512e Advanced Format, storage density can continue growing and pre-existing compatibility can be maintained. Hurray!