After a few weeks of rumours, SeagateНs senior product manager Barbara Craig has confirmed to Thinq that сwe are announcing a 3TB drive later this year,о 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 PCНs three-decade legacy has once again reared its DOS-era head, revealing that many of todayНs PCs are simply incapable of coping with hard drives that have a larger capacity than 2.1TB. ж
The root of the problem is the original LBA (logical block addressing) standard, which canНt 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. ItНs a limit that until now has seemed so far off in the future that hardly anyoneНs considered it a problem. сI think thatНs what everyone thought,о says Craig. сNobody expected back in 1980 when they set the standard that weНd ever address over 2.1TB.о ж
Craig explains that сwe need to extend that to Long LBA addressing,о 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. ж
According to Seagate, this includes the 64-bit versions of Windows 7 and Vista, as well as modified versions of Linux, but it doesnНt 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.
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сThereНs also a GUID partition table (GPT) that needs to be implemented,о explains Craig, сfor the master boot record.о Current master boot record partitions are limited to 2.1TB, so a new GPT partition table would also need to be used to see beyond this.
Of course, this is all fine if youНre using a 3TB drive as a secondary disk, but there are more problems to overcome if you want to use that 3TB drive to boot your OS. Unfortunately, the master boot record is a key part of the standard BIOS setup that motherboards have used for decades. ж
GPT was originally proposed as a part of IntelНs Extensible Firmware Interface [EFI]; a user-friendly setup system designed to replace the clunky ASCII-based BIOS. This specification is now looked after by the United EFI Forum (UEFI), and one of its many new features is a larger LBA addressing scheme, which would enable enough addresses to be handed out to drives with greater capacities than 2.1TB. ж
However, this presents a big problem, as many standard motherboards donНt feature a UEFI system. Some manufacturers, such as MSI, have introduced UEFI to a select few boards, but UEFI is still not the de facto standard. WhatНs more, any RAID drivers, if appropriate, will also need to support Long LBA if you want to put your 3TB drives in an array. ж
Basically, with the original LBA limit set at 2.1TB, it seemed pointless for anyone else to prepare for any capacity beyond this, so we now have a situation where many hard drive controllers, BIOSes, drivers and operating systems are all set with caps of 2.1TB, and this is going to take an industry-wide overhaul to overturn. ж
Although this involves a massive amount of work, Craig says that сmany of the partners - you know the operating system, the BIOS, the RAID controllers - everyone has attacked it, and I think about 80 percent of the infrastructureНs ready to support it.о ж
сOn the UEFI standard, weНre going to a Plugfest next month,о he continues, сto ensure that everybody is ready, and the IDEMA Group is also supporting them.о According to Craig, the preparation for the move to 3TB drives has also meant cooperation with other hard drive manufacturers. ж
Assuming that all the issues get ironed out, Seagate says that itНs planning to launch its first enterprise-level drives with more than 2.1GB of storage space at the end of this year.
Tags: windows xp, bios, extensible firmware interface