Quote Originally Posted by -Boris- View Post
Finally, chips from AMD has always been nicely ordered, pointing at a mostly hand made layout. I can imagine that it leads to an uneven power usage and unnecessary long circuits and timings. And wastes die space.
lol, it is the exact opposite. hand layout is much better. humans are better at finding eulerian paths and coming up with clever layouts. computers cant really do that with all of the design rules and other parameters as effectively. the difference in performance is 2.6-7x faster with custom designed circuits.

really what happens is a coder will simulate his module and make sure it reaches the targeted timing, which is usually much higher than actual delay to assure robust operation. if the logic cant reach the speed it is either rewritten or circuit designers optimize it. in certain logic families it must be entirely custom designed.

circuits that are custom designed are usually things like power gating, clock distribution, and analog circuits such as pll's, dll's, and memory controllers/ io pads.