A change is coming into the hard drive market place this year, after planning has been going on for about a decade or so. The change in question? Raising the size of hard drive sectors from 512 bytes to 4096 bytes, or 4KB. Why is this important, and why should you care?
First some background about what’s going on: the main reason for raising the amount of data a single sector can hold is to improve efficiency (and therefore speed), as well as support for even larger hard drives. You see, the storage capacity of hard drives has increased immensely year over year, but the way the data is organized on the platters has not kept pace. And there are good reasons why the organizational side hasn’t changed the same way, even though the manufacturers were aware that they would be running into issues eventually and needed to do something about it.
The problem with smaller sector sizes that basically every hard drive up to 2010 used is that they are increasingly inefficient. The data stored on hard disks isn’t just your actual data, but also overhead that enables important functionality like error correction, without which you couldn’t rely on your data being stored correctly. Going from 512 byte sectors to 4KB sectors allows better and more efficient error correction algorithms to be used, which will result in higher speeds, but also increases capacity of the drives, as more of the drive space can be used for user data, and less for error correction.
Now this all sounds very good and reasonable, but what’s the catch? As alluded to, some older OSes and applications cannot properly deal with these new 4K sector drives, the most popular one being Windows XP. So if you haven’t upgraded to Windows Vista or Windows 7 yet, you might want to avoid getting one of these new drives (Macintosh users running Tiger or higher are not affected). You can find some helpful general information from Western Digital about these new drives, or if you would like to get the nitty-gritty technical background, head on over to AnandTech.