We don't usually use them all simultaneously, but recently we did just for a little while. Kind of focuses your attention! Its all in the timing.
Dual runway...
BTW The 6th runway is already designed, just waiting for more traffic before they build it.
Edited to add:
Take a look
here to see the layout. The 6th will go below and parallel to the far runway, to give 4 parallels and a pair of parallels at 90 degrees.