Advanced Format and 4K Sector Support

Advanced Format and 4K Sector Support

The hard disk drive industry is transitioning to larger physical sector sizes called Advanced Format. The default sector size has been 512 bytes since the advent of the personal computer. Advanced Format sectors are also called 4K sectors, because each physical sector now holds 4096 bytes. While the physical size is 4K, the disk drive processor presents the data over the cables to the computer as ordinary 512 byte sectors. This is called 512 byte emulation, or 512e.

The operating system will run slightly faster if it is "aligned" to the Advanced Format hard drive. Reading data from aligned or misaligned drives is the same. Writing data to a misaligned drive is slightly slower. Reading data accounts for the great majority of disk drive usage. During setup, Windows 7 detects Advanced Format disk drives and adjusts the partitions automatically for alignment; Windows XP does not.

How to determine if your disk drive uses the Advanced Format
There are two easy ways to make this determination. Visually, you can inspect the drive label for the following logo graphic:

If the drive is already installed, you can use the Seagate Partition Offset Utility to query the drive properties:

Windows 7 and Windows Vista basics
Windows 7 and Vista detect Advanced Format drives and automatically set properly aligned partitions. Windows 7 Service Pack 1 adds several driver updates for Advanced Format drives. You should have Win7-SP1 before you begin your installation for optimal performance results. Please read the Microsoft support information below.

You may use DiscWizard to clone data from an old drive to a new one. The partitions will be automatically aligned by DiscWizard.

Windows XP basics
Many Seagate disk drives with Advanced Format utilize a technology enhancement called SmartAlign™. SmartAlign technology maintains consistent hard drive performance, even when it encounters hard drive partition misalignment conditions while writing data to the disk drive. SmartAlign technology is a utility-free solution, saving time and extra steps in hard drive integration.

To be fully optimized for Advanced Format disk drives, you can use DiscWizard  Add New Disc function to do pre-partitioning with proper alignment before installing Windows XP. This step is not required if you adopt SmartAlign to manage the write data activity, which it does automatically. With an aligned partition, there is less activity for SmartAlign to manage.

You may use DiscWizard to clone data from an old drive to a new one. The partitions will be automatically aligned by DiscWizard. To correct misalignment after the Windows XP operating system is established, you may use DiscWizard to make a full Disc Backup to an external USB storage device and then use DiscWizard Disc Recovery to restore the image back to the first drive. The partitions will be automatically aligned by DiscWizard.

For special circumstances when Windows XP has been installed with partition misalignment on a Seagate or Samsung disk drive which does not offer SmartAlign technology, then Seagate offers a special utility to realign the partition and data. The Seagate Advanced Format Utility should only be used on Windows XP. Always make a full backup of your data before running this utility. If you believe you need this Windows XP software, please contact Seagate Support by email and provide the serial number of the disk drive.

Apple OS X and Linux basics
Macintosh systems since MacOS X 10.4 (Tiger) support direct-attached disk drives using Advanced Format 4K Sector disk drives. Only the GPT style partitions will produce properly aligned partitions. The older Apple Partition Manager does not support Advanced Format drives.

Linux distributions based on the 2.6.34 kernel provide full support for Advanced Format 4K Sector disk drives. Limited support for 4K began in 2.6.31.

Seagate support information

Microsoft support information

Intel support information
Intel® Rapid Storage Technology Support for 4k sector disks

Other software
Paragon Alignment Tool (PAT)

Industry support information
IDEMA - Advanced Format Downloads

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