Hardware Reference
In-Depth Information
since then Microsoft and other OS vendors have been incorporating it into operating sys-
tems. The GPT uses 64-bit LBA numbers, meaning disks of up to 9.4ZB (8ZiB) can be
managed.That'sequalto9.4
billion
terabytes,alimitthatwon'tbereachedanytimesoon.
Figure 7.13
illustrates the differences between MBR and GPT partitions.
Figure 7.13
GPT includes a backup for partition entries and the partition table header.
Although GPT breaks the 2.2TB barrier from a drive formatting perspective, other ele-
ments must be in place for GPT to be usable in a PC. To format or recognize a GPT-
formatted disk, you need an OS that supports GPT. That alone allows you to use GPT-
formatted disks as secondary (data) disks, but to boot from a GPT-formatted drive, you
also need a motherboard with a UEFI BIOS or UEFI Boot option.
Table 7.24
summarizes
the requirements to break the 2.2TB barrier.
Table 7.24 Operating System GPT Boot/Data Disk Support
