- Super Scalar & SIMD Architectures: Modern CPUs can handle more operations per cycle, but only if workloads are structured to exploit this potential.
- Caches Matter: Larger caches are powerful but require careful memory access patterns to avoid penalties. Random access? Prepare for a performance hit.
- Pipelines & Branching: Long pipelines and speculative execution make predictable branching critical. Branch mispredictions are now more expensive than ever.
- Numa Challenges: Memory access across nodes can incur significant performance penalties. Optimizing for cache and memory locality is essential.
- Numa Pitfalls: Sharing memory across nodes can lead to bottlenecks, and even lightweight I/O operations may introduce disproportionate penalties.
- CPU Scaling Limits: Some CPUs sacrifice consistent performance for higher burst speeds. Always check the fine print when choosing hardware for heavy workloads.
- Speculative Execution Risks: While powerful, speculative execution can lead to unpredictable results if not carefully managed.
Modern CPUs reward careful structuring of workloads. Whether it’s reducing branching, maximizing cache efficiency, or using hierarchical data structures for shared memory, the rules of optimization are evolving with the hardware.
