Amdahl's Law

Will give you hints about the usefulness of certain design operations. All about speedups.

CPU time is
IC * CPI * 1/clock frequency (tclk/clock period)

Compiler affects IC.
ISA also affects IC (RISC vs CISC)
Complex instructions get mapped to simpler instructions in microcode.

Different parts of the CPU time can be impacted.

Take the original time, some fraction of it is affected by the enchancement. This part is alpha.
k is the speedup due to the enhancemtn

Example:

Conclusion-
Everything is about the CPU time equation.
Stall cycles play into it too.
The compiler has a really big role to play.

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