4 ms·

The information moves faster than electrons move. It's shocking for slow individual electrons move!

• kragen 4y ago
  That's true for information transmission, like what happens in wires, but as I understand it, switching in semiconductor diodes, transistors, and vacuum tubes actually requires the electrons to move in and out of depletion zones (or the vacuum). Switching in relays or pneumatic valves requires moving solid assemblages of atoms around instead. That's why it's slower, even though the drift velocity in the wires connected to a relay is the same as in the wires connected to a transistor.
  • djmips 4y ago
    Good points! It's true that switching times in transistors is a thing! There's even something called gate delay! I remember working on a system where 1 ns delays were available in a chain of transistor gates on the silicon die. You would do some tests and adjust the delay +/- by adding or removing a gate (selectable via some logic) and once you got the good results in your calibration you'd lock in the delay. This allowed for some synchronous signals when there was variation from different foundry processes and a variety of PCB layout distances between chips.