There have been naysayers through the years that have predicted that rotating media technology will at some point have exhausted the limits of delivering capacity increases. Time and time again the hard drive industry has proved them wrong. Proving their point again, a technology that has served the hard disk drive industry well through the multitude of capacity increases over the last 30 years is storing data on 512-byte sectors, but using this architecture is coming to an end. We live in an environment where consumer, commercial, industrial, utilities and government users have an insatiable need for ever increasing levels of storage. The hard drive industry is responding to this need by implementing a new layout of data sectors on the disk surface from legacy 512-byte sectors to 4,096-byte (4K) sectors. This advancement scales the capacity per disk, making possible higher-capacity drives while continuing to reduce cost per gigabyte. Deploying 4K sector architecture also facilitates a more efficient use of error correction code technology for improved performance and reliability.

Advanced Format Fig 2
Advanced Format Fig 3

Disk drive manufacturers have agreed that all new PC and notebook drives introduced after January 2011 will be 4KB formatted. WD has already introduced several 4K sector-based drives using its proposed industry term of Advanced Format. Advanced Format technology increases the bit density to enable increased storage capacities and also provides a more powerful error correction scheme for enhanced data integrity. Error correction can be improved by as much as 50% through the use of longer error correction codes (ECC) and a 7%-11% increase in format efficiency is projected. One 4K sector contains the equivalent data of eight 512 byte sectors for a more robust system with less overhead segments while also saving critical space. This all adds up to improved format efficiency and data reliability for the user. It also translates into faster access to data and reduced errors. And as this technology continues to evolve, manufacturers will be able to deliver larger capacities (over 2TB) with advanced correction capabilities. 

512 byte emulation

Most users can also expect seamless integration because hard drives with 4K sectors work with most current operating systems, such as Windows Vista, Windows 7 and Mac operating systems. However, Advanced Format (and future 4K) sectors are not optimized for outdated operating systems such as Windows XP. To serve its vast installed base, WD offers WD Align software, a simple utility that allows Advanced Format drives operating under Windows XP to run at full performance.

4K sectors are the next evolution in the hard drive industry. You decide whether it is revolutionary, but it does go a long way to satisfy the ever growing user need for larger and more efficient storage capacity solutions. The future of advanced storage is promising as 4K sector drives provide faster access to data, reduced errors and the ability to deliver larger and larger capacity hard drives.