This is one of those few moments when saying Big Data is actually a well-used term.
[0]: https://soundcloud.com/linear-digressions/whats-the-biggest-...
Check out slides 21 and 22 from [1]. There are parts that will process 4 PB/s (!)
[1] http://www.slideshare.net/SparkSummit/distributed-data-proce...