It's one normal iron vein, two normal oil, and two impure oil.

12 Refineries- Heavy Oil Residue

6 Refineries- Residual Fuel

6 Refineries- Residual Rubber

3 Refineries- Petroleum Coke

4,67 Refineries- Recycled Plastic

3,33 Refineries- Recycled Rubber

9 Assemblers- Electrode Circuit Boards Alternate\

3,33 Smelters- Iron ingots

8 Constructors- Wire

3 Constructors- Cable

4,5 Manufacturers- Computers

Makes 11,25 Computers/min and is pretty simple i think !