Whats the Skinny on FAT32?

Think of the fresh hard drive you've just purchased as a huge cabinet with no drawers or folders installed. The way in which the operating system (OS) organized the files in that cabinet is through the use of a file system. Each OS has its own preferred way of storing files, and the main onea in use at FAT 16, FAT 32 and NTFS. (The term FAT refers to File Allocation Table) The chart below show the major OSs and the systems they use!

Formatting your hard drive:
The first thing to do with that hard drive is prepare it in the manner appropriate for your operating system. Typically, you will the DOS utility FDISK in order to format your drive. The utility will ask you whether (assuming the drive is bigger than 500MB, which it most likely is) you want to enable 'large disk support'. If you answer Yes, you'll be using FAT32, and if you said No, you'll be using FAT16. After you've made at least one partition, you can now format the drive.

FAT 16 vs. FAT 32.
The big difference between these two methods of creating a File Allocation Table is the way that they manage the individual clusters on the drive. Cluster are the actual storage 'cubicles' that are set up on the hard drive, and they can be used by the operating system to store files.

When one is using FAT16, each one of these clusters has a maximum size of 32Kb. FAT16 itself refers to the fact that the a 16bit number is used to keep track of the number of clusters. A 16bit number has a maximum value of 65 536, so the maximum amount of space is can manage is 65 536 x 32kb, which works out to 2.1GB (2 097 152 kb). The cluster size is also important, because if a file is 2kb, it still uses up an entire 32kb cluster, meaning that 30kb of space is wasted. The size of the clusters can vary proportionally, with 32kb the size used in 2.1GB hard drive partitions.

The end result is that for example, an 8GB hard drive using FAT16 will have to be split up into 4 x 2GB hard drives. There is also lots of waster space due to the large cluster size.

Using FAT32, a 32bit number is used to keep track of the number of clusters. The maximum number of clusters is 4 294 967 296, versus 65 536. That means there is the possibility of tracking up to a maximum of 2,000 GB of space. That also means that cluster size can now be much smaller than 32kb, so there is less wasted space. You can use 4kb clusters instead, which means a lots more saved space, especially if you have lots and lots of small files on your hard drive. The difference can be amazing sometimes, running from 5 to 15% just by upgrading to FAT32 from FAT16.