Summary
Highlights
The internal data bus, also known as registers, is located inside the CPU. It determines how much data can be moved within the CPU at one time, acting like holding cells or a 'to-do list' for the processor. The size of this bus (e.g., 32-bit or 64-bit) dictates the amount of data the CPU can work with simultaneously.
The address bus is a set of wires that tracks where data is stored and retrieved from memory (RAM). It acts as the CPU's bookkeeper for memory access and dictates how much RAM the CPU can work with. For instance, a 32-bit CPU can theoretically access up to 64 gigabytes of RAM.
The external data bus is the pathway for information to enter and exit the CPU. It's a collection of wires or pins, and its width determines how much data can move in and out, and how fast. Most modern external data buses are 64-bit wide.
Bandwidth refers to the amount of information that can move into and out of something within a set period. It can be increased by either increasing the speed at which data travels or by providing more 'lanes' (paths) for the data to move through.
A very fast bus connects the CPU to the chipset, often called the frontside bus (FSB), processor-side bus, or CPU bus. These are different names for the same high-speed connection.
Hyper-threading allows a single CPU to accept two independent sets of instructions simultaneously, effectively creating multiple 'lanes' for processing. For hyper-threading to function, the CPU, chipset, BIOS (with enablement), and operating system must all support it.