Finally, a bootable 3TB hard drive—for select systems
It’s been nearly two years since we saw the first 2TB drives hit the market. You’d think we would have gotten 3TB drives months ago. It’s not that hard, is it? Turns out, it’s pretty complicated. We’ll get into all that in a second, but in the meantime, here’s what you need to know: Western Digital’s new 3TB Caviar Green drive is the first internal bootable 3TB drive to hit the market. It’s not the first 3TB drive—Western Digital and Seagate both have external versions—but it is the first bootable 3TB drive.
So, why are we only now seeing bootable 3TB drives? Because most computers are running on kludged-together legacy systems, that’s why! Hard drives have historically been divided into 512-bit sectors. Your drive’s master boot record, which tells the BIOS where everything is on a given drive, is 32-bit, so it can only address a number of sectors equal to one 32-bit integer’s worth. Two to the 32nd power is 4,294,967,296; multiply that by 512 bytes and you get 2.19TB, which is how big a partition can be before the MBR runs out of room to figure out where everything is. To overcome this obstacle, your PC needs to meet a laundry list of requirements: It needs a 64-bit OS, a motherboard that supports UEFI (the successor to the BIOS), and support for GPT partitions rather than MBR.
The 3TB Western Digital Caviar Green.
If your PC meets those requirements, you should be able to create a bootable 3TB partition on WD’s new 3TB Caviar Green. Just to make sure, Western Digital includes an off-the-shelf HBA (host bus adapter) with a carefully vetted chipset/driver combo—HighPoint’s RocketRaid 62x—which allows users to bypass their motherboard’s south-bridge storage drivers. In our experience, most motherboard south-bridge drivers aren’t quite ready for 3TB drives. When we tried formatting ours from the Intel ICH10R on our test bed, it showed up as an 800GB drive, and we’ve heard reports of similar issues from other south-bridge drivers, so WD’s inclusion of an HBA with a tested driver set was wise.
We were able to create a working Windows 7 install on a 3TB GPT partition on the 3TB Caviar Green using the HBA. We benchmarked the drive on our standard motherboard test bed against the 2TB Caviar Green (reviewed May 2009) and Seagate’s similarly spec’d 2TB Barracuda LP (reviewed October 2009). We tested all three drives using the RocketRaid HBA with GPT partitions. Thanks to its four 750GB platters—and phenomenal areal density—the 3TB Caviar Green was the fastest in average sequential read and write speeds, topping 92MB/s in both. However, it lagged behind the other drives in our PCMark Vantage and Premiere Pro benchmarks.
The 3TB Caviar Green is fast (inasmuch as a low-power drive can be), enormous, and—given that it ships with a useful two-port 6Gb/s SATA HBA—a good deal at $240 (although, as always, it’s cheaper to buy two 1.5TB drives, or even two 2TB drives). But the percentage of users with the UEFI-compatible hardware necessary to create a 3TB boot partition is still tiny, and motherboard SATA drivers are still flaky when it comes to partitions greater than 2.19TB. That said, most Maximum PC readers who are buying huge storage drives are booting from smaller, speedier drives, so the partition-size limit likely won’t bother you, and WD deserves massive props for getting the drive out there. Now that drives exist that require UEFI, hopefully motherboard vendors will have incentive to jump on the bandwagon.
Mobo UEFI support still lacking; lags behind 2TB drives in some tests.
WD Caviar Green 3TB
WD Caviar Green 2TB
Seagate Barracuda LP 2TB
Avg Read (MB/s)
Random-Access Read (ms)
Avg Write (MB/s)
Random-Access Write (ms)
Burst Write (MB/s)
Premiere Pro Encode (sec)
Best scores are bolded. All drives tested on our hard drive test bench: a stock-clocked Intel i7-930 CPU on an Asus P6X58D Premium motherboard with 6GB DDR3, running Windows 7 Professional 64-bit. All tests performed using HighPoint RocketRaid 62x HBA.