What Does RISC and CISC Mean in 2020?

Many today say the difference between RISC and CISC has become irrelevant. Is that true? And if not what exactly is the difference between modern RISC and CISC CPUs?

Erik Engheim
The Startup
Published in
25 min readJul 27, 2020


Apple has now released the M1 Apple Silicon chips, and after all the fuss you may be wonder what makes it different from an intel or AMD processor? You have probably heard M1 referred to as an ARM processor and that ARM is a so called RISC processor, unlike x86 processors from intel and AMD.

Read More: Why Is Apple’s M1 Chip So Fast?

If you try to read up about the difference between RISC and CISC microprocessors, you will hear a lot of people tell you that RISC and CISC doesn’t matter anymore. That they are essentially the same. But is that really true?

Okay, so you are confused and you want some straight answers. Well, then this article is the right place for you to start.

I have plowed through a ton of comments and writing on this, sometimes by the engineers themselves that created these chips, so you don’t have to waste time on this.

Read more: Random Facts About ARM, x86, RISC-V, AVR and MIPS Microprocessors

First I will start with some of the basics you got to understand before we begin to answer some of the deeper questions such as RISC vs CISC. I am putting in headlines, so you can skip over the stuff you already know.

Here are some of the topics I will cover in this article:

  • What is a CPU?
  • What is an Instruction Set Architecture (ISA)
  • Why pick one ISA over another?
  • How are RISC and CISC instruction-sets different?
  • CISC Philosophy
  • RISC Philosophy
  • Pipelining
  • Load / Store Architecture
  • Compressed Instruction-sets
  • Microcode vs Micro-operations
  • How is a Micro-operation different from a RISC instruction?
  • Hyper-threading / Hardware threads
  • Does RISC vs CISC still make sense?



Erik Engheim
The Startup

Geek dad, living in Oslo, Norway with passion for UX, Julia programming, science, teaching, reading and writing.