Make sure you are running gzip silently. The overhead created by STDOUT on the zip/unzip process is significant

Uhh . . . huh?

Even with --verbose, gzip only prints one line for every file it processes. That's hardly what I'd call significant. Especially not in a case like this where each file averages 200M of uncompressed data!

-sauoq
"My two cents aren't worth a dime.";