Care to explain why?

(you can find more info in the manpage for your shell)

    $ cat foo | bar

ends up creating two processes and a pipe. The foo file is first read by cat and then written onto the pipe (which bar then reads).

    $ <foo bar

is an input redirection: foo is opened for reading and bar's standard input fd is set to that open file (so the file's data is only read once)

for reading files and transferring over the network: the limit is always going to be the IO devices, not an extra context switch and a few extra copies...

s/always/usually/. Depending on the disks involved and your network hardware (either a super-fast link, or even a system with a slow CPU and cheap network hardware that expects the drivers to do the heavy lifting in software), it actually could end up CPU-constrained.

But for the usual case where it is I/O-constrained, you can often get files across more quickly by throwing CPU at reducing the total amount of bandwidth required by, e.g., using something like bzip or pbzip:

  pbzip2 < file | nc $host $port

And on the other side:

  nc -l $port | pbzip2 -d > file