Explained here. The article contains a gentle refreshers about ISA, pipelining, CISC vs RISC, CPU architecture, out-of-order execution… Before it dives into Apple’s not so secret architecture.
M1 is not a CPU. It is a system of multiple chips put into one large silicon package. It departs from the traditional PC architecture. Its Unified Memory Architecture addresses the traditional limitations of shared CPU-GPU memory.
Intel and, to a lesser extent, AMD are left in an undesirable position, as their business models do not fit the new paradigm. (…)