This week Western Digital announced that it had added a 2.5 Terabyte (TB) and 3 TB hard drive model to its Caviar Green family of Internal SATA drives. The company says they are the world's largest capacities to date on a single drive.

While the thought of having more disc space on your computer is appealing, Digital Home readers should note that these high capacity drives may not work with their present computer systems.

Simply speaking, in order for a computer to boot from a hard drive whose capacity is in excess of 2.19 TB, the operating systems and motherboard must support something called the Unified Extensible Firmware Interface (UEFI). UEFI is not required to use the drive as secondary storage, however, special drivers are still needed.

If your computer uses a 64 bit operating system and has a recent motherboard, then you should be able to make use of one of these new drives, however, Digital Home recommends, you vist the WD information sheet at to determine the suitability of your system.

“Customers will be able to take advantage of this breakthrough capacity point now for secondary external storage in legacy 32-bit systems that run on Microsoft Vista or Windows 7 platforms.” said Jim Morris, executive vice president and general manager of WD’s client systems storage group.

The WD Caviar Green 2.5 TB hard drives (model number WD25EZRSDTL) and 3 TB hard drives (model number WD30EZRSDTL) are covered by a three-year limited warranty and will sell for $189 USD and $239 USD.

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