Factorio Forums

Here's my take on how you really get the most bang for your buck when it comes to beacons. Name shamelessly taken from Forever Peace.
Note the 240% boost. The beacons in my NanoForge, as well as the Assembler itself, all use the Productivity 3 modules.
That's (12*15%) 180% Beacon Boost to a single building.
Put in the ingredients for ten items, and you get 34 back.

Damn, I wanted to do something like this first.
That's the upper limit of productivity, right?
I'll have to make a table of minimal costs for everything at 340% productivity one day.

As far as I can tell. I experimented with several different layouts and arrangements, and couldn't get more than 12 affecting the assembler at the same time.
Fortunately, there's still room for belts in and out, so it's compatible on a modular basis for a full assembly line.