When Western Digital announced its 3TB My Book Essential, the company revealed that the external drive's underlying Caviar Green hard drive would be available shortly. Now, some two weeks later, the Green gets its moment in the spotlight—and a bright one at that. Although Seagate beat WD to the punch on the external front, the Caviar Green is the first internal hard drive to become available with three terabytes of total capacity.
To hit this latest milestone in mechanical storage, Western Digital stacks new platters that squeeze 750GB onto a single 3.5" disc—a 50% jump in per-platter capacity from the 2TB Caviar Green. Do the math, and you're looking at four platters for the three-terabyte drive. A 2.5TB model will also be available with the same platter count.
Like other members of the Caviar Green family, these new offerings have spindle speeds in the neighborhood of 5,400 RPM. Western Digital fine-tunes rotational speeds to hit acoustic and power-consumption targets, so there's some variation from one model to the next. The 2.5 and 3TB Caviar Greens both feature 64MB of cache and 3Gbps Serial ATA interfaces, though. They also make use of Advanced Format, which ditches the traditional 512-byte sector size in favor of more efficient 4KB sectors.
Despite its advanced formatting, the Caviar Green actually emulates 512-byte sectors to avoid potential software incompatibilities. This creates another problem because Master Boot Record partition tables can only address up to 232 blocks, effectively capping the Green's capacity at 2.19TB. The industry's solution is to use newer GUID Partition Tables (GPT), which can address up to 264 blocks, allowing the 3TB Green to achieve its full potential. GPT is relatively new, and it's not supported in Windows XP, so neither are the new Caviar Greens. Western Digital notes that XP users may be able to get the drives working at full capacity with third-party controller cards, but it's not making any promises.
Even Windows 7 and Vista users face hurdles if they want to run the Caviar Green as a boot drive rather than as secondary storage. Doing so requires a 64-bit version of the operating system and a motherboard with one of those newfangled Unified Extensible Firmware Interface (UEFI) BIOSes. Since UEFI-equipped mobos are relatively rare, Western Digital is shipping the Caviar Green with an auxiliary storage controller that gets around that particular limitation. The controller in question is a HighPoint RocketRAID 62X with dual SATA ports and a PCI Express x1 interface.
Our 3TB Caviar Green didn't arrive in the Benchmarking Sweatshop until late last week, so we don't have more in-depth coverage for you just yet. High-capacity drives take a while to work their way through our comprehensive benchmark suite, and I'm in Taipei, Taiwan for most of this week. Testing is already underway and a full review is in the works, though. If you can't wait, Western Digital says that the 3TB Green is already shipping in the channel. The drive is slated to sell for $240 when bundled with the HighPoint card, while the 2.5TB model will be available for $189.