At the level they're describing things there's a continuous stream of bits with no boundaries. This is not RAM. Some of those bits will be used to separate log

At the level they're describing things there's a continuous stream of bits with no boundaries. This is not RAM. Some of those bits will be used to separate logical "sectors" (which will be larger than your octets), some for error correction... I wouldn't be surprised if the capacity in units that don't hurt your head will end up more like 120 terabytes, not 200.