Speed or security? Speculative execution in Apple Silicon
(eclecticlight.co)
Making a CPU do more work requires more than increasing its frequency, it needs removal of obstacles that can prevent it from making best use of those cycles. Among the most important of those is memory access. High-speed local caches, L1 and L2, can be a great help, but in the worst case fetching data from memory can still take hundreds of CPU core cycles, and that memory latency may then delay a running process.
Making a CPU do more work requires more than increasing its frequency, it needs removal of obstacles that can prevent it from making best use of those cycles. Among the most important of those is memory access. High-speed local caches, L1 and L2, can be a great help, but in the worst case fetching data from memory can still take hundreds of CPU core cycles, and that memory latency may then delay a running process.