Meanwhile at the Ship and Shovell

"Ah," the barmaid said, "my favourite round." The order is a pint of Fursty Ferret, a pint of Badger Ale, a pint of Amstel and a pint of cider. But why would a barmaid have a favourite round?

Well, the Amsel and cider use automatic pumps. The barmaid places a glass under each tap and sets them running. Ferret and Badger, being proper ales, are served from hand pumps. Again, she places a glass under the two taps and, grasping a handle in each hand, draws both pints simultaneously. With the result that all four pints are ready together, in the minimum elapsed time.

Parallel processing, you can't beat it.