How much time does it take to copy "Kla.TV-Offline" from one harddisk to one or two others??

Expect copying ,Kla.TV-Offline‘ (1.7 TB) to ONE harddisk, to take 12 hours

Expect copying ,Kla.TV-Offline‘ (1.7 TB) to 2 harddisks simultaneously to take 16 hours

These calculations apply to the cheapest available harddisks in the market, each costing around 70$. More expensive harddisks typically are faster.