ARM: The ReadyNAS will support files up to 16TB (terabyte) in size.
x86: Depending on which firmware you were running on initial setup or when you last wiped the NAS via a factory default (whichever came later), the ReadyNAS will support files up to 2TB (terabyte) or 16TB (terabyte) in size.
Sparc: The ReadyNAS will support up to 2TB (terabyte) file size.
Some protocols, such as HTTP will have a limitation where maximum file transfer size can be much less.