There aren't multiple threads on a single file in my example code,only the capability becuase WriteOut was wrapped in a sub to be made a thread. Only one writer thread is created, to atomically dequeue processed data and write it out.

As for the overhead issue, while in its current state the overhead doesn't merit separate threads, if this grows and starts using some form of HTML Parser in the parse stage then the split begins to make more sense as HTML parsers can be slower than downloading the document to feed them, separating the processes allows the download to finish faster and make room for the parsing.