GPT is the short of GUID Partition Table, and it is one
of architectures for partitioning disk drive to store data. Generally speaking, it
was created to accommodate the larger partition sizes. Apart from size, GPT disks
also provide more partitions to build. GPT disks can grow to a very large size.
Theory speaking, one GPT disk
can be up to 2^64 logical blocks, which are commonly sized in 512b, in
length. Windows 95/98/ME, Windows NT4, Windows 2000, Windows 2003
32-bit, Windows XP 32-bit version have a limitation of 2TB per physical
disk. Windows file systems currently are limited to 256 terabytes each.
So at most you can create 128 partitions on GPT disk.
Master Boot Record (MBR) is a special type of boot sector at the very
beginning of partitioned computer mass storage devices like fixed disks
or removable drives intended for use with IBM PC-compatible systems and
beyond. The MBR holds the information on how the logical partitions,
containing file systems, are organized on that medium. Besides that, the
MBR contains executable code to function as an operating
system-independent chain boot loader in conjunction with each
partition's Volume Boot Record (VBR). What is wrong with MBR
MBR disks support only
four partition table entries, and if you need more partitions to store different
data, you have to change one primary partition to logical partition, and then,
creaste extended partitions. MBR partitioning rules are complex and
poorly specified. An MBR partition is identified by a two-byte field,
and coordination is necessary to avoid collision. Today there is no
single authoritative list of partition identifiers.
The conversion between GPT disk and MBR disk
GPT disk, a more advanced style, GPT partition style, is
specially designed for the larger hard drive (disk capacity is larger than 2TB)
while MBR disk is widely accepted nowadays. Sometimes, you need to convert GPT disk
to MBR disk, or convert MBR disk to GPT disk. But you find that the function in
Windows Disk Management would be greyed out. Futionately, AOMEI Partition Assistant Professional (PA Pro) enables you to realize conversion between GPT
and MBR without data loss.
Besides, the GPT disk partition format is well defined
and fully self-identifying. Although GPT disks have those advantages, you can not
make a disk both GPT and MBR. However, all GPT disks contain a Protective MBR.