Comment 9 for bug 1860200

Go back and read #3 again. I'm talking about running like this:

duplicity--->backend process 1
         --->backend process 2
         ...
         --->backend process N

Where each backend process handles gzip,gpg,plain as needed. This gives N-way multiprocessing and uses N cores for both IO and processing. In this scenario a multithreaded gzip would actually slow down the processing if it were to use all cores.