Tech Talk (01/04)
NTFS vs. FAT32 (revisited)
by Brian K. Lewis, Ph.D.*
Member of the Sarasota Personal Computer Users Group, Inc.
I think it's time to take another look at some of the pros andcons of the two file systems that are available if you have Windows XP or if you want to upgrade to XP. WinXP offers you the choice of either FAT32 or NTFS as your hard drive file system.The FAT32 (File Allocation Table) file system is what you used in Windows 98, SE and ME. The NTFS system was first available with Windows NT, then Win2000 and now Windows XP. The NTFS stands for "New Technology File System" just as the NT in Windows NT meant "New Technology". Wow! Anyway, these are two very different methods of organizing and recording information on the files stored on your computer's hard drive. WinXP can use either file system. In fact, you can have both file systems on the same computer and easily transfer files between them.
NTFS can work with single drive partitions up to 8 petabytes, that's 8 followed by 15 zeros. Apparently Microsoft has actually tested NTFS with a 19 terabyte partition (19 followed by 12 zeros). If you have trouble with the large numbers used in hard drive sizes here's a table that might help.
UNIT |
ABBR: |
BITS- |
POWER |
Kilo |
(K) |
Thousand |
3 |
Mega |
(M) |
Million |
6 |
Giga |
(G) |
Billion |
9 |
Tera |
(T) |
Trillion |
12 |
Peta |
(P) |
Quadrillion |
15 |
Exa |
(E) |
Quintillion |
18 |
Zetta |
(Z) |
Sextillion |
21 |
Yotta |
(Y) |
Septillion |
24 |
Compare this large drive capability of NTFS with the FAT32 system that is limited to about 2 terabytes. Don't think this may not be a problem? Just remember that we now have drives with more than 200 GB capacity. Terabyte sizes are not that far in the future. FAT32 has other problems as well. As you increase the volume or partition size in a FAT32 system, the cluster size also increases. The cluster size ranges from 4 K to 32 K. You reach the 32K maximum with drives larger than 32 gigabytes, at least according to Microsoft. Some references indicate otherwise. However, the following table is taken from two different Microsoft references on cluster size in FAT32.
| Partition size | Cluster size |
512 MB to 8,191 MB |
4 KB |
8,192 MB to 16,383 MB |
8 KB |
16,384 MB to 32,767 MB |
16 KB |
Larger than 32,768 MB |
32 KB |
The whole point of the cluster size problem is that the minimum file storage space is ONE cluster. Therefore, if you have a 512 K file or a 1 K, it will take up one full cluster. On the 40 GB drives that are now commonly available, that cluster takes 32 thousand bytes (32K) of space. However, the default cluster size with an NTFS partition is 4K even up to the maximum partition of 8 petabytes. So file storage is far more efficient with NTFS. You might say "So What?" with my 80 GB drive why should I worry about file size? That may be true for a while, but there are other efficiencies provided by NTFS as well as some problems if you are converting a FAT32 system to NTFS. As I mentioned, NTFS is a very different filing system than FAT32. Except for very small files, NTFS is much faster in locating files because of its B-tree structure. Now I know this means nothing to you unless you are a programmer. So lets look at this a little. In a FAT file structure each folder entry contains an index into the file allocation table. This identifies the starting cluster of the folder. When you want to load or view a file, the system has to walk the folder structure to get to each segment of the file. First it finds the starting cluster of the folder, then the starting cluster of any subfolder, then the starting cluster of the file, and finally, the clusters that contain the file. In mathematical terms, the average time to find a file using FAT32 is N/2, where N is the total number of files in the File Allocation Table. You can also see that to find the file, the command to load or read the file must contain the complete path (all the directories and subdirectories) that must be searched to find the final file. Not a rapid process, especially when you realize that even a 2 GB hard drive can have 12-15,000 files! I have seen 40 GB drives with over 60,000 files and occupying less than 20 GB of drive space. These were not drives with a lot of data on them. Instead the majority of these are system files created by Windows, Internet Explorer, Outlook/ Outlook Express, etc. They are also program files created during the installation of your applications.
In the NTFS system, the file index is stored quite differently by using the B-tree structure. This diagram outlines the general setup:
This is also referred to as a clustered index. The entry point to the index is through the root at the top of the tree. The branches are used to navigate to the leaf or page level which identifies the file we wish to use. I'm not going to beat this to death as I know you don't want to become programmers. However, this structure does allow for faster searching for files. In mathematical terms, the average time is the log of N. As long as LogN is less than N/2, the file will be found faster in NTFS. (Consider that the logN of 10,000 is 4, while N/2 is 5,000.) For small files, NTFS can even store them in the Master File Table which increases the speed of reading the file.
NTFS has more benefits such as reliability. It is a transaction logging system which allows NTFS to recover quickly from a disk problem or power failure. It does not guarantee that no user data will be lost. However, each transaction is logged before it is written to the disk. If a power failure or other disk problem occurs, NTFS checks the transaction log to see if the transaction was completed successfully. If it was not completed, NTFS backs out the transaction. No incomplete modifications to the hard disk are allowed.
O.K., so NTFS sounds like the file system of choice. What are the problems? If you have purchased a new system with Windows XP pre-installed, you probably already have NTFS. However, some early systems were installed with 512 byte (0.5K) clusters. These systems have shown a massive slow down in disk I/O performance. These systems need to have the cluster size increased to 4K. Unfortunately, to do this you need a third party software application since there is no conversion available from Microsoft. One application that has been recommended, but that I haven't tested, is Paragon Partition Manager. It is available from this web site: http://www.partition-manager.com/n_pm_main.htm at a cost of $40.00.
Partition Magic, ver 8.0 is also supposed to be able to make this conversion. The user comments on this version of Partition Magic have been quite positive.
The other problem is for upgraders from Windows 98, 98SE and ME. It seems that the Windows XP upgrade keeps the FAT32 system when these computers are upgraded. You can convert to the NTFS system after the upgrade. So you may have to use the partition management software I mentioned in the previous paragraph. Just be certain you select the 4K clusters as part of the conversion. For Windows 2000 users, you are given the option of which file system you want when you upgrade. However, choosing NTFS results in a system with 512 byte clusters. It would be nice if Microsoft would eliminate this problem in the first service pack for XP. There are many desirable aspects to using Windows XP. The NTFS file system is one part in that it contributes to the reliability of the operating system. I have converted my main computer to XP and have been very satisfied with the result. The reliability of this NTFS file is one large part of my satisfaction. Another part is that I have not had to defrag the hard drive even after almost a year of use. At this point, it is less than 7% fragmented. This is much better than the performance of any previous version of Windows.
If you decide to finally make the move to XP, remember to convert to the NTFS file system. You will benefit from this change.
*Dr. Lewis is a former university & medical school professor. He has been working with personal computers for more than thirty years. He can be reached via e-mail at bwsail@yahoo.com or voice mail at 941/925-3047. :
Copyright 2004. This article is from the January 2004 issue of the Sarasota PC Monitor, the official monthly publication of the Sarasota Personal Computer Users Group, Inc., P.O. Box 15889, Sarasota, FL 34277-1889. Permission to reprint is granted only to other non-profit computer user groups, provided proper credit is given to the author and our publication. We would appreciate receiving a copy of the publication the reprint appears in, please send to above address, Attn: Editor. For further information about our group, email: admin@spcug.org/ Web: http://www.spcug.org/
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