Intel makes CISC chips (Complex Instruction Set Computer) but Apple Silicon is a RISC chip (Reduced Instruction Set Computer) sometimes you see the letters ISA, which in this context means Instruction Set Architecture.

Making this up for the sake of an example, a CISC chip might have instructions for painting a two-story house, painting a one-story house, painting a toolshed, and painting a playhouse. A RISC chip would just have an instruction for painting a wall. In order to paint any of those structures, the software has to issue the “paint a wall” instruction several times for each kind of wall.

The problem with CISC chips that they end up being very complex (duh!) with a lot of instructions that are not often used and might get overlooked. The chip runs hot and slow since it has so much internal “machinery.” Also, the complexity makes it hard to scale down the architecture, say from 12nm to 10nm. Scaling down the architecture makes the chip faster, but it runs hotter, because the CISC chip has so much to do.

RISC chips are much simpler and run cooler, but software needs to give them more instructions to do the same job. It ends up being simpler, faster, and more efficient because the chip is always being optimally used. It is easier to scale down the architecture to speed up a RISC chip. Since it is simpler, other features can be added to the chip. The Apple Silicon chips won’t need a separate graphics chip, just as iPhones and iPads today don’t need one today. You’ve never seen a debate about whether Apple should use NVIDIA or Radeon in the iPhone or iPad because they don’t use either one. They use Apple Silicon with the graphics on the CPU chip.

RISC chips are capable of fantastic performance. The super computer in Japan that is the fastest in the world has a RISC architecture.

Macs running on Apple Silicon will be wickedly fast, both in computation and in graphics. Apple will add an emulation layer for Intel programs (Rosetta) for the next few years, and since that is running on a RISC chip, there won’t be much loss of performance for software written for Intel.

The PowerPC chip, which Apple used to have, was a RISC chip, so they know all about that architecture. When they switched to Intel, they added an emulation layer called Rosetta that would let PowerPC programs run. The next few operating systems were double coded, and their development tools allowed developers to write double-coded software. They didn’t discontinue those features for several years until the PowerPC software had flushed out of circulation. They are repeating that with a new emulation layer and Rosetta 2, so there is no reason to avoid buying an Intel Mac right now. macOS operating systems will continue to run on Intel Macs computers for a long time.