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ntfs max disc size

ntfs max disc size

ntfs max disc size

What is the maximum size hdd nt can handle?

RE: ntfs max disc size

This all depends...

Pre Service Pack 4 Atapi can only handle a maximum of 8GB per partition, but not on the active boot partition which is limited to 7.8GB. But thats still post installation since the boot partition is limited to a created size of 4GB because of a FAT limitation under Windows NT, since the drive must be converted to NTFS after the first boot.

NTFS is not really limited in size since the actually size limit is 2^64 bytes (16 exabytes or 18,446,744,073,709,551,616 bytes). I assume they would just upgrade the limit if anyone actually came up with a drive with that much space. But there is also a 2 terabyte limitation with any file system due to hardware limit in the partition table.

Alternatively you could easily extend the size of any other partition, besides the boot partition, after Windows NT is installed.

Hopes this helps.

John D. Saucier
Registry Backup

RE: ntfs max disc size

Here is anarticle for some consideration also as there is a hidden portion of the install that has dos limits when you install you are limited to a 4gb system partition. you can then feel free to use something like partition magic to resize the partition.

Although Windows NT 4.0 can in theory support partitions of up to 16 exabytes in
size using the NTFS file system, the maximum size of the system partition is
limited to 7.8 gigabytes (GB).


The system partition is defined as the partition containing the files needed for
the initial system startup. For Windows NT, the files are NTDetect.com, NTLDR,
Boot.ini, and sometimes Ntbootdd.sys.

A boot partition is defined as the partition containing the system files. For
Windows NT, this is the partition containing the %SystemRoot%\System32 folder.

The system partition and boot partition can be on the same partition or on
different partitions. Because there can be multiple operating systems installed
on a single computer, a computer can have multiple boot partitions, but a
computer has only a single system partition.

When an Intel-based computer first boots, a number of things occur that result in
the operating system being loaded and started. This process, known as the
bootstrap process, has inherent hardware and software limitations beyond which
Windows NT cannot operate. It is these limitations that prevent Windows NT 4.0
from using a partition larger than 7.8 GB as a system partition.

During the bootstrap process, the only mechanism available to Windows NT (or any
other operating system) to access the drive is a set of functions in the BIOS
known as Interrupt 13 (INT13). The INT13 functions allow low-level code to read
from and write to the drive by addressing a specific sector on the drive. When
the INT13 architecture was developed back in the early 1980s, the possibility of
multi-gigabyte hard disks was not taken into consideration. The INT13 functions
define 24 bits to describe a sector on the hard disk. This breaks down to a
maximum of 256 heads (or sides), 1024 cylinders, and 63 sectors. With these
numbers, only 256*1024*63 (or 16,515,072) sectors can be used with INT13
functions. At a standard 512 bytes per sector, this is 8,455,716,864 bytes, or
approximately 7.8 GB. Note that for most modern drives, the computer's BIOS must
support some form of sector translation for the BIOS functions to address the
first 7.8 GB of disk space. The BIOS in virtually all modern computers supports
"Logical Block Addressing," which allows INT13 functions to address the first
7.8 GB of drive space independent of the drive's physical geometry.

The INT13 functions are the only means available to the operating system to gain
access to the drive and system partition until the operating system loads
additional drivers that allow it to gain access to the drive without going
through INT13. Therefore, Windows NT 4.0 cannot use a system partition larger
than 7.8 GB. In fact, the entire system partition must be entirely within the
first 7.8 GB of the physical disk. Windows NT can use a 7.8-GB system partition
only if the partition begins at the start of the physical drive.

NOTE: Partitions other than the system partition are not affected by the these

Other operating systems, such as Microsoft Windows 95 OEM Service Release 2,
Microsoft Windows 98, and Microsoft Windows 2000, can boot from larger
partitions because these operating systems were written after the computer
industry defined a new standard for BIOS INT13 functions (the "INT13
extensions") and implemented this new functionality on manufactured
motherboards. Because Windows NT 4.0 was written before this new standard was
invented, Windows NT 4.0 is unaware of this new technology and is unable to use
its features.

When you are installing Windows NT 4.0, you can create a system partition with a
maximum size of 4 GB. This occurs because Setup first formats the partition
using the FAT file system. If you want to use an NTFS partition, the partition
is converted to NTFS after the first reboot. The FAT file system has a file
system limitation (unrelated to any BIOS limitations) of 4 GB. When you perform
an unattended installation, use of the ExtendOEMPartition directive in an
Unattend.txt file can expand the system partition to a maximum of 7.8 GB.

In the future, additional limitations may come into play as well. Although the
NTFS file system can address 16 exabytes of disk space in a single partition,
current disk-partitioning schemes store partition information in structures that
limit partitions to 2^32 sectors, or 2 terabytes, in size. The ATA hardware
interface uses 28-bit addressing, which supports drives that are 2^24 sectors,
or 137 GB, in size. These limitations may apply to partitions other than the
system partition as well.

Note that file system limitations and hardware limitations exist independently of
each other, and the most restrictive of the two is the determining factor in the
maximum partition size. Another factor to consider when you are troubleshooting
partitioning problems is that hard disk manufacturers often use "decimal
megabytes" (1 megabyte = 1,000,000 bytes), whereas Windows NT uses "binary
megabytes" (1 megabytes = 1,048,576 bytes). Using both definitions of a megabyte
in calculations can often account for "lost" disk space. Also, this article
assumes a sector size of 512 bytes in all calculations. Although a 512-byte
sector has become a de facto industry standard, it is possible that disk
manufacturers could produce drives with a different sector size. This would
result in a corresponding change in partition limits. Partitions are based on
cylinder, head, and sector calculations, not on byte calculations. Therefore, a
change in bytes per sector causes a change in bytes per partition.

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