COSTS OF PIPELINING

(H&P pg 135 )

This performance improvement is not free.

• If a unit in the data path is used in more than one pipeline stage, it must be replicated (or contention would occur)
  • (Example: since the ALU is used in EX, the PC must be incremented (in IF) by a separate increment)
  • (If the instruction set were to include instructions in which several ALU operations are involved, we would have to have several ALUs)