How many stages?
The more stages, the less combinational logic within a stage, the higher the possible clock frequency
- More stages can complicate control. Dec Alpha has 7 stages for FX instructions, and these instructions have a define-use delay of one cycle for even basic FX instructions
- Becomes difficult to divide up logic evenly between stages
- Clock skew between stages becomes more difficult
- Diminishing returns as stages become large
Superpipelining is a term used for processors that use a high number of stages.