• the computer designer must be aware of changes in five domains to design architecture that sustains
    • IC logic technology
    • Semiconductor Dynamic RAM
    • Semiconductor Flash
    • Magnetic Disk Technology
    • Networking Technology

Bandwidth Over Latency

  • bandwidth: is the total amount of work done in a given time

  • latency: is the response time between the start and completion of an event

  • bandwidth growth has outpaced latency growth, a simple rule of thumb is bandwidth grows by at least the square of the improvement in latency, designers should plan accordingly

Scaling of Transistor Performance and Wires

  • feature size: minimum size of a given transistor or wire
    • \(7 nm\) chips are underway as of 2017
    • the density of transistors increases quadratically with a linear decrease in feature size
  • transistor performance generally improves with decreased feature size
    • but wires in ICs do not

  • in wires, as feature size reduces wires get shorter but the resistance and capacitance per unit length gets worse

  • in general, wire delay scales poorly compared to transistor performance
    • power dissipation limit and wire delay are bigger problems in design compared to transistor switching delay