![]() Historically, drive manufacturers state capacity in "kb's" of 1,000 bytes rather than the 'binary' kb of 1024 bytes = no doubt this 'convention' was adopted for the same reason that screen manufacturers advertise their diagonal size (so they can suggest their products are 'bigger' than they really are :-) ) Unfortunately, such a 'hack' then breaks both the boot sequence (and many other parts of Windows XP which also have this 512 byte 'assumption' built in), however a 4k sector MBR format works just fine if you are using LINUX Actual drive limit If the MBR on a drive is 'hacked' to use a 4K sector size (the size of actual sectors on high capacity / multi-TB drives), the limit becomes 16TB. ![]() ![]() To handle larger drives, instead of 'fixing' MBR, Microsoft invented the 'GPT' partitioning scheme. This gives us the maximum size of a single MBR partition of 2048Mb. The MBR partition table 'assumes' the disk sector size is 512 bytes, and uses 22 bit addressing. The limit is imposed by Windows XP Disk Manager and how it uses the 'MBR' format to define partitions on the drive surface. Expect it to take approx 10 Hr per Tb of data that needs re-aligning XP hard drive capacity limit I use the excellent MiniTool Partition Wizard Home Edition 8.1.1 which not only lets you re-align an existing partition but even copes with moving the data on an 'active' (bootable) partition). To align later, in theory you can use either the Hitachi Acronis Alignment Tool (which ignores the existence of 'dynamic' disks) or the WD Align Tool (only available to those who have registered their WD drive). The MS Win2000 vintage 'diskpar' tool can be used to check the offset of an existing partitioned and formatted disk = see here (see also MS KB929491 and MS KB923076) ![]() You can either use a 3rd party tool to get the 'correct' offset 64 (x512 = 4 x 4k) OR set a 'jumper' to 'tell the drive' to add an extra +1 (512byte) sector offset (not all drives have this jumper). The result is that NTFS formatting a 2TB partition will take about 14 hours and data transfers will be between 4x and 8x SLOWER than they should be :-). This will cripple your hard disk performance, since it results in everything 'starting' at a point 7/8th the way through a 4kb sector (so, every 'write' to the drive means an existing 4k sector has to be read and then the last 7/8th replaced with new data). Microsoft's moronic Windows XP Disk Manager creates Partition with a 63 (x512 = 3.9 x 4k) sector 'offset'. >2Tb Drives with XP WARNING - almost all current hard drives use a 4kb sectors with 512b sector 'emulation'. ![]()
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