The maximum size of the SD card for the 810 has already been clarified: 32GB How big can the external hard disk be, which can be connected via USB connection in the glove compartment? (It must definitely be one without external power connection, clear.) What size makes sense here? Among other things access time (1 TB needs longer than 80GB), another side a TB currently lies at 50 Euro, less with us significantly less. Which formats can the 810 Media Player play (is here primarily about movies)? I have no idea about the things, but can remember that with my satellite receiver only the second hard disk (for HD recording) really funzte (the first one was too lame).