[Source]
Cluster sizes in the context of data recovery
A cluster or block (same thing but different OSes refer to it differently) is the smallest addressable unit within the file system regardless the file system we’re talking about. Each time we read a file, the Operating System looks up cluster addresses of the clusters allocated to this file and to correctly interpret the cluster address we need to know the cluster size and the offset to cluster zero. If we don’t know the size of a cluster and/or the location of cluster zero on the hard drive or SSD then a cluster address is useless. This is the reason why some file systems store the structure where these values can be looked up twice (or even more).
The same is true for file recovery software that is trying to make sense of a corrupt file system. And as the OS, the software can try to find the blocks where the file system stores the offset to cluster zero and the cluster size. In absence of these blocks the file recovery tool can maintain a lookup table with default values like the tables below. But more intelligent tools can work out the location of cluster zero and the clustersize without relying on the value being known. All tools below are capable of the latter and DMDE even allows you to override the values.
NTFS
| Volume size | Windows 7, Windows Server 2008 R2, Windows Server 2008, Windows Vista, Windows Server 2003, Windows XP, Windows 2000 |
|---|---|
| 7 MB–512 MB | 4 KB |
| 512 MB–1 GB | 4 KB |
| 1 GB–2 GB | 4 KB |
| 2 GB–2 TB | 4 KB |
| 2 TB–16 TB | 4 KB |
| 16TB–32 TB | 8 KB |
| 32TB–64 TB | 16 KB |
| 64TB–128 TB | 32 KB |
| 128TB–256 TB | 64 KB |
| > 256 TB | Not Supported |
FAT16
| Volume size | Windows 7, Windows Server 2008 R2, Windows Server 2008, Windows Vista, Windows Server 2003, Windows XP, Windows 2000 |
|---|---|
| 7 MB–8 MB | Not supported |
| 8 MB–32 MB | 512 bytes |
| 32 MB–64 MB | 1 KB |
| 64 MB–128 MB | 2 KB |
| 128 MB–256 MB | 4 KB |
| 256 MB–512 MB | 8 KB |
| 512 MB–1 GB | 16 KB |
| 1 GB–2 GB | 32 KB |
| 2 GB–4 GB | 64 KB |
| 4 GB–8 GB | Not supported |
| 8 GB–16 GB | Not supported |
| > 16 GB | Not supported |
Note The asterisk (*) means that it is available only on media with a sector size greater than 512 bytes.
FAT32
| Volume size | Windows 7, Windows Server 2008 R2, Windows Server 2008, Windows Vista, Windows Server 2003, Windows XP, Windows 2000 |
|---|---|
| 7 MB–16MB | Not supported |
| 16 MB–32 MB | Not supported |
| 32 MB–64 MB | 512 bytes |
| 64 MB–128 MB | 1 KB |
| 128 MB–256 MB | 2 KB |
| 256 MB–8GB | 4 KB |
| 8GB–16GB | 8 KB |
| 16GB–32GB | 16 KB |
| 32GB–2TB | Not supported |
| > 2TB | Not supported |
exFAT
| Volume size | Windows 7, Windows Server 2008 R2, Windows Server 2008, Windows Vista, Windows Server 2003, Windows XP |
|---|---|
| 7 MB–256 MB | 4 KB |
| 256 MB–32 GB | 32 KB |
| 32 GB–256 TB | 128 KB |
| > 256 TB | Not supported |
Recommended data recovery programs (DiskTuna Approved):
UFS Explorer
Very well rounded tool supporting many filesystems and advanced storage technologies such as RAID and numerous encryption techniques. Moderately difficult to use. This is your best bet when trying to recover data from NAS devices.
[Mac/Win/Lin]{FAT|NTFS|ReFS|HFS+|APFS|EXT|BTRFS|UFS|XFS|ZFS|+More +RAID}
R-Studio
Well rounded tool with a good mix of filesystem, RAID, and encryption support. Supports professional data recovery hardware from DeepSpar.
[Mac/Win/Lin]{FAT|NTFS|ReFS|HFS+|APFS|EXT|UFS|XFS|+RAID}
DMDE
Another favorite for some pros. This is my work horse logical data recovery tool. Be warned that this tool can write to patient drive, but it will never do so using the default configuration.
[Mac/Win/Lin/DOS]{FAT|NTFS|ReFS|HFS+|APFS|EXT|BTRFS|+RAID}
Note EXT = Ext2/3/4, FAT = FAT12/16/32/exFAT