SDXC is limited to 2TB?. SDUC is limited to 128TB. While there are no SDUC cards, the maximum card you can currently buy is 2TB. This means to go any higher, you would automatically be in the SDUC territory. Currently, only the professional version of the hardware sold will support SDUC. The philosophy is that professionals are more likely to need higher end cards, whereas the general public can get away with SDXC cards. If you feel you might need to use SDUC cards, then you would need to buy a professional version of the hardware sold by Senitrus.