Cluster size of your partition

The following tables illustrate below the various cluster size limitations for each particular file systems. Why should you care about the cluster size of your partition? Because you can save a great deal of space by choosing the right file system. For example, if your file is 1K in size and your cluster size is 32K, then you've just wasted 31K of "slack" space for that file.

FAT/FAT16 (DOS/Windows 95/Windows NT)

Partition Size	Cluster Size
0 - 127MB	2K
128 - 255MB	4K
256 - 511MB	8K
512 - 1023MB	16K
1024 - 2047MB	32K

Note: FAT16 is limited to 2GB per partition.

FAT32 (Windows 95 version 950B)

Partition Size	Cluster Size
less than 260 MB	512 bytes
260 MB - 8 GB	4K
8GB - 16GB	8K
16GB - 32GB	16K
32GB or more	32K

Note: A partition formatted as FAT32 can only been seen in Windows 95 version 950B. Eariler versions of Windows 95, DOS 6.22, or even Windows NT 4.0 cannot recognize FAT32 partitions!

NTFS (Windows NT)

Partition Size	Sectors/Cluster	Cluster Size
512MB or less	1	512 bytes
513MB - 1024MB (1GB)	2	1K
1025MB - 2048MB (2GB)	4	2K
2049MB - 4096MB (4GB)	8	4K
4097MB - 8192MB (8GB)	16	8K
8193MB - 16,384MB (16GB)	32	16K
16,385MB - 32,768MB (32GB)	64	32K
32GB or more	128	64K

Note: You cannot use NTFS file compression if your cluster size is larger than 4K.

These cluster size tables are courtesy of Zubair Ahmad, a MCT/MCSE