google alebo microsoft.com a napisat si tam file system limits alebo FAT12 limit apod.
u FAT32 a NTFS limity zavisia aj od implementacie v OS. OS to totiz nemusi mat implementovane uplne, ale pouzije napr. len 24bitov z 32bitov apod. to je asi aj ten limit "v praxi" o ktorom pises. Teoreticky by FAT32 mal zvladnut snad az 128TB (2^32 * 32768bytov cluster ?). Hlavne MS ma take tendencie sak predsa 2TB disk musi stacit vsetkym, ale ze o 3roky mozno nebude to vie aj MS ale o 3roky predsa budu chciet aby si im zacvakal minimalne 150$ za ich najnovsi smejd takze mam pocit ze oni snad tie ich neopodstatnene "obmedzenia" vo Win vyrabaju schvalne.

priklad pre win2k a NTFS
http://www.microsoft.com/technet/prodtechnol/window s2000serv/reskit/prork/prdf_fls_pxjh.mspx?mfr=true
Maximum file size
2^64 - 1 KB (Theoretical)
2^44 - 64 KB (Implementation)

Maximum volume size
2^64 clusters (Theoretical)
2^32 clusters (Implementation)

Files per volume
2^32 - 1