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Date: Tue, 13 Oct 2015 07:54:27 +0200
From: "Nicklas Karlsson (nicklas DOT karlsson17 AT gmail DOT com) [via geda-user AT delorie DOT com]" <geda-user AT delorie DOT com>
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Subject: Re: [geda-user] A lesson from gnet-makefile
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> > Suppose a resistor had an attribute that meant  “100 ohm shunt terminator”. Imagine a component with a pair of pins identified by an attribute as a differential input. Put them on the same pair of nets, and the netlister could deduce that the pair is a balanced transmission line and the the resistor needs to be close to the input.
> > 
> > Of course, we’d need a layout program that could accept this info.
> 
> Indeed, and while autorouters may help in some cases, the general
> feeling among the few professional PCB designers I've met is that 
> auto placement is typically poor, to put it mildly. The problem is 
> much harder than autorouting, and it shows.

I also agree about poor usefulness of auto placement. The firts problem is the decoupling capacitors. Maybe it would work better with autoplacement in several steps:
  1. Disperse components.
  2. Place decoupling capacitors.
  3. As a first approximation place tightly coupled components as groups which of curse may be very hard to define.
  4. Autoplace this group of components there the tightly coupled components may have to be fine tuned.