Can FAT Make Your Drive Leaner?

August 19

Question: Steve,

I have a three-gigabyte hard drive in my computer running Windows 98. Under Disk Cleanup "they" recommend converting (data storage system) to "FAT32" so it can store data more efficiently (i.e., get me more disk space), run programs faster, and use fewer system resources.

If this was "seamless," I assume it would be done automatically. What are the drawbacks they are not telling me about? Will it affect my programs, networking (Ethernet), browsing the WWW? Should I back up my drive before I attempt this? Does it live up to its claims?

Thanks.

-- John, Coon Rapids, MN

Answer: John,

Mostly, "they" are correct: FAT32 lives up their claims. It certainly does store data much more efficiently, and your computer may run programs faster and use fewer system resources. Will the conversion to FAT32 increase performance so much that you won't be able to recognize the new speed demon siting on your desk? Probably not.

What Is FAT?

Because Windows needed to stay compatible with earlier releases, it inherited its file storage system from good old DOS. DOS kept track of files stored on your disk drive or hard drive with File Access Tables (FAT). The total contents of a file might be stored in several different places on a disk; the FAT made sure that all the pieces could be found when you needed them.

The File Access Tables are special, invisible files that are always stored in the same place on the disk. When your computer's operating system makes any changes to a normal file, say "resume.doc", it first looks inside the FAT files and reads from a table that tells it where "resume.doc" is stored on the disk. After changes are made to the file, your computer records those changes in the FAT files so you can find "resume.doc" the next time you need to change it, move it, copy it, or delete it.

Remember that FAT was developed back when a 20-megabyte hard drive was phenomenally vast storage. Now, you can't fit a typical application into 200 megabytes. Because of this DOS legacy, FAT has a data storage limit of 2 gigabytes per partition. This means you can probably only store about a dozen modern applications per partition. Once your storage needs exceed this threshold, you must subdivide your hard drive into two or more "partitions." What exactly are partitions? Partitions behave like separate hard drives (such as "C:" and "D:") even though they reside inside the same physical piece of hardware. You have a 3GB hard drive, and you use FAT16, so you must already have at least 2 partitions. Or you have about a gigabyte of unused storage space on your hard drive. FAT32 has an upper limit too, but it's something ridiculous that will probably seem claustrophobic in a few years.

While the FAT files might be invisible, they occupy space, and it's a lot more than you would expect. For a one-gigabyte partition, as much as 40 percent of it is wasted by FAT. Small wonder they call it FAT, eh? This waste is because FAT stores data in large 32 kilobyte groupings called "clusters." FAT32 stores data in tiny clusters of 4 kilobytes. For our hypothetical one-gigabyte partition, the waste from FAT32 would only be about 4 percent How does a smaller cluster size yield less waste? Imagine you are packing the trunk of your car for a weekend trip. It's a lot easier to pack in a freezer's worth of burgers than it is to fit a Weber grill and a couple of lawn chairs. FAT32 gives you a "tighter" fit on your hard drive, so you can store a lot more data in your computer's "trunk."

The Risk Of Converting

If FAT32 is so great, what's the catch? Why doesn't your computer automatically convert without bothering to ask you? Because conversion is not without risks. The process changes every single file on your computer, and if it suffers a disruption (power outage, crash, system reset) while converting from FAT to FAT32, you could end up with an unreadable hard drive. I strongly recommend you back up your important files to removable tapes or disks before you begin the conversion. Don't worry about those 200-meg applications; you can always reinstall them. Preserve your documents, spreadsheets, e-mail boxes and those doodles you made with the paint program.

Another risk involves older disk maintenance tools, like early versions of Norton Utilities or low-level virus scanners. These tools might not work properly in a post-FAT32 world. If the drive maintenance software is old enough not to indicate whether it was designed for Windows 98, there is a chance that it could damage to your data.

A final complication arises if you intend to later upgrade this partition to Windows NT. Windows 98 can be upgraded to NT if the file system is FAT, but not if the file system has been converted to FAT32. Windows NT's file system (NTFS) is superior to FAT32, but you have to descend back down to FAT before you can ascend to NTFS. For these file-system gymnastics, you will want to buy third-party partition management software like Partition Magic.

Before you execute the conversion, write down how much free space you have on the hard drive. Note that if you have only a few megs of left on the drive, you will need to free up some "wiggle room" to run the conversion. After what should be a "seamless" conversion, it's a good idea to run a "defrag" on your new FAT32 partition. The de-fragmentation process shuffles the smaller clusters on your hard drive so they are more tightly organized. Now compare the free space count to the old FAT number. You will probably be very happy with the new headroom.

--Steve Morman, Help! Menu Guru