Do you know what RISC is, what about CISC, and why does it matter?

Do you know what RISC is, what about CISC, and why does it matter?

The battle between RISC (Reduced Instruction Set Computing) and CISC (Complex Instruction Set Computing) has shaped the history of computing, yet many may not fully grasp their significance in modern technology. Let’s look the evolution of these architectures, their differences, and why this distinction still matters.

The origins of RISC date back to the early 1980s, yet for decades, CISC processors dominated the market. CISC processors, such as those used in the first IBM PCs, were designed with a broad set of instructions, making them capable of performing complex tasks in fewer lines of code. However, as computing power increased, the inefficiencies of CISC processors became apparent.

In contrast, RISC processors, designed with a smaller set of simple instructions, allowed for faster execution and lower power consumption. Because their instruction sets are smaller, the internal circuitry of RISC CPUs is simpler, meaning instructions can be executed more quickly and efficiently.

The story begins in the 1960s, when computers were slower and memory was limited. At that time, it made sense for CPUs to have complex instructions to reduce the number of lines of code, a necessity for efficient programming with limited resources. However, as computing power and memory capacity increased in the following decades, the need for these complex instructions began to diminish.

In 1974, Intel introduced the Intel 8080 processor, which later became the foundation for the Intel 8088 used in the IBM PC. This marked the beginning of the consumer desktop PC revolution. At the same time, the CISC architecture continued to dominate, with its emphasis on rich instruction sets, which helped simplify programming.

In the early 1980s, UC Berkeley, funded by DARPA (the agency that also funded the development of the Internet), developed the first RISC processor, a design that was simpler, faster, and more efficient than anything before it. The RISC approach gained traction in academic and research circles, but its adoption in consumer computing was slower due to the vast amount of existing code written for CISC processors.

By the 1990s, as computers became faster and memory became more abundant, the appeal of RISC grew. However, transitioning existing systems to RISC meant rewriting massive amounts of software, making the change cost-prohibitive. It wasn’t until the rise of smartphones in the 2000s that RISC processors, particularly the ARM architecture, became widespread. Companies like Qualcomm and Samsung popularized ARM processors, making them the foundation of mobile computing.

Apple’s journey through RISC and CISC architectures has been an interesting one. From 1994 to 2006, Apple used PowerPC processors, which were based on RISC. This was a period when Steve Jobs and Apple embraced RISC for its performance benefits and efficiency. However, in 2006, Apple transitioned to Intel-based CISC processors, which enabled better compatibility with software and improved performance. The shift helped Apple grow into the dominant force it is today.

But Apple’s story doesn’t end there. With the advent of its M-series chips, starting with the M1 in 2020, Apple returned to RISC, this time leveraging ARM-based architecture for its MacBook, iMac, and Mac mini. The transition allowed Apple to further improve performance while maximizing battery life—a key advantage in mobile devices that has now extended to laptops.

In conclusion, while CISC processors once dominated, the advent of RISC has proven to be essential in the evolution of mobile and laptop computing. Today, we continue to see the benefits of RISC architecture, particularly in power efficiency and performance for devices like smartphones and laptops. The choice between RISC and CISC is not just a technical debate but one that defines the usability, efficiency, and longevity of modern computing devices.