TestDisk and PhotoRec are using a 64 bit internal data offset representation.
IDE LBA28 addressing is limited to 128 GB HD.
IDE LBA48 addressing is limited to 131072 TB.
PC/Intel MBR partition table is limited to 2 TB.
GUID Partition Table (GPT) can be up to 18 exabytes (Supported since TestDisk & PhotoRec 6.9).
The most common limitation is to have an OS that doesn't handle IDE LBA48 addressing mode.