What is an instruction set? (AKIO TV)

Summary

This script explains the concept of CPU instruction sets, which are like languages that CPUs 'speak'. It contrasts CISC (Complex Instruction Set Computing) with RISC (Reduced Instruction Set Computing), detailing their advantages and use cases. CISC CPUs, like Intel's x86, are powerful but less efficient for simple tasks, while RISC CPUs, like ARM, are energy-efficient and ideal for mobile devices. The script also discusses how companies like Intel and ARM Holdings approach their instruction set architectures differently.

Takeaways

• 💻 **CPU's Role**: A CPU processes data and instructions, where instructions are crucial for telling the CPU what to do with the data.
• 📝 **Instruction Set Defined**: An instruction set is a collection of commands that a CPU can understand and execute.
• 🔢 **Binary Nature**: Instructions are binary codes (zeros and ones) that the CPU interprets to perform operations.
• 📱 **Variety in Instructions**: Different CPUs have different instruction sets; some may have more complex or varied instructions than others.
• 🏎️ **Complexity in SISD**: SISD (Complex Instruction Set Computing) CPUs have a wide array of instructions, which can perform complex operations efficiently but consume more power.
• 🚀 **Efficiency in RISC**: RISC (Reduced Instruction Set Computing) CPUs are designed for efficiency and simplicity, using fewer transistors and less power, ideal for mobile devices.
• 📲 **Application in Devices**: SISD CPUs are common in desktops and laptops, while RISC CPUs dominate in mobile devices due to their power efficiency.
• 🛠️ **x86 and ARM**: x86 is a SISD instruction set by Intel, used across many generations of CPUs, while ARM is a RISC set used in mobile devices.
• 🏢 **Intel's Monopoly**: Intel is the sole legal manufacturer of x86 CPUs, with AMD being an exception due to a historical license.
• 🌐 **ARM's Licensing Model**: ARM Holdings licenses its architecture to multiple companies, allowing them to produce their own ARM-based CPUs, unlike Intel's closed model.

Q & A

What is an instruction set in the context of a CPU?

An instruction set is the set of all the operations a CPU can perform. It's like a language that the CPU understands, consisting of machine code made up of zeros and ones.

Why are instructions important for a CPU?

Instructions are crucial because they tell the CPU what to do with the data it processes. Without instructions, the CPU wouldn't know how to handle the data it receives.

How does the instruction set vary across different CPUs?

The instruction set varies because different CPUs have different machine codes for the same operations. One CPU's 'add' instruction might be different from another's.

What is the difference between CISC and RISC instruction sets?

CISC (Complex Instruction Set Computing) includes as many instructions as possible, which can handle complex operations efficiently but requires a more complex CPU design. RISC (Reduced Instruction Set Computing) minimizes the number of instructions, resulting in a simpler and more energy-efficient CPU design.

Why are CISC CPUs less efficient for simple workloads?

CISC CPUs are less efficient for simple workloads because their complex design consumes more power and the complex operations advantage is not utilized in basic tasks like web browsing or email reading.

What is the advantage of using RISC CPUs in mobile devices?

RISC CPUs are advantageous in mobile devices because they are designed to be energy-efficient, which is ideal for devices that run on battery power.

Which instruction set is x86, and who developed it?

x86 is a CISC instruction set developed by Intel. It has been used in Intel CPUs for a long time, including the Core i7 8700K and the older Pentium 4.

Why is Intel the only company legally allowed to make x86 CPUs?

Intel is the only company legally allowed to make x86 CPUs because they have been successful in preventing other companies from producing them, although AMD also has a license to produce x86 CPUs.

What is ARM, and how did it become popular?

ARM is a RISC instruction set that was developed during the same era as x86. It became popular in the 2000s when mobile devices gained traction and there was a need for energy-efficient CPUs.

How does ARM Holdings' business model differ from Intel's?

ARM Holdings sells licenses to make ARM CPUs to other companies, allowing them to create their own designs based on the ARM instruction set. In contrast, Intel keeps its x86 architecture for itself and produces its own CPUs.

Which companies are known for making ARM-based CPUs?

Companies like Qualcomm, Apple, and Samsung are known for making ARM-based CPUs, which are commonly used in smartphones and other mobile devices.