Microarchitecture

  • Hardware implementation strategy

  • This is the level that actually includes:

    • pipelines

    • out-of-order execution

    • branch prediction

    • caches

    • execution units

    • reorder buffers

    • µop translation

  • Two CPUs can share the same ISA but have completely different microarchitectures.

  • Example

    • Both run x86-64:

      • Intel Skylake

      • AMD Zen

    • but internally they are very different machines.