We do not support the USB HDD because the extension HDD box has different control chipset, some of it is working well, but some of it is not; therefore, we do not announce that the USB HDD will be supported. For this reason, we do not suggest user to use External USB HDD in our DVR, and not only that the HDD has the compatible issue potential. Otherwise, some of External USB HDD speed is too slow to might make the backup video lost. Too many uncertainty issues cause we do not know that how to support it; in PC base, it will be easy to support; but in standalone, all the driver has to save in the memory before, so that is the reason we are really hard to do it so far.
Shield Technology