Seagate’s senior product manager Barbara Craig has confirm “we are announcing a 3TB drive later this year,” but the move to 3TB of storage space apparently involves a lot more work than simply upping the areal density.
The ancient foundations of the PC’s three-decade legacy has once again reared its DOS-era head, revealing that many of today’s PCs are simply incapable of coping with hard drives that have a larger capacity than 2.1TB.
The root of the problem is the original LBA (logical block addressing) standard, which can’t assign addresses to capacities in excess of 2.1TB. Originally set out by Microsoft and IBM as a part of the original DOS standard, the original LBA standard assigns an address to each 512-byte sector – the smallest physical block of data on a hard drive.
Unfortunately, though, the range of addresses is limited to capacities of 2.1TB. It’s a limit that until now has seemed so far off in the future that hardly anyone’s considered it a problem. “I think that’s what everyone thought,” says Craig. “Nobody expected back in 1980 when they set the standard that we’d ever address over 2.1TB.”
Craig explains that “we need to extend that to Long LBA addressing,” in order to get around this. Long LBA basically increases the number of bytes used to define an LBA address in the command descriptor block, but it also requires a supporting OS.
According to Seagate, this includes the 64-bit versions of Windows 7 and Vista, as well as modified versions of Linux, but it doesn’t include Windows XP. Not only that, but you may not even be able to see 2.1TB of a 3TB drive when using Windows XP.
Seagate says that its own tests have shown that as little as 990MB of a 3TB drive could be available to you when using XP.