Reading large text file from network (SMB)
Reading just 160 bytes at a time could be bad for performance, especially if you are using the older SMB 1 protocol.  SMB 2.0 introduced pipelining, which allows the client to issue another request before the previous one has completed.  Therefore, with SMB 1, you would have to wait for each request to be finished — including network and disk latency — before making the next read.  If the read requests are too small, then performance could suffer badly.

What is a good buffer size?  Microsoft's KB 223140 suggests that somewhere between 4 kB and 60 kB could be ideal — in any case, much more than 160 bytes.