// HARDWARE MODULE 03

CPU Die Layout & Architecture

CYBERGRIND.ORG
HW-003
v1.0 // 2026
CPU Die Components

ALU — Arithmetic Logic Unit

Performs all integer arithmetic (add, subtract, multiply) and logical operations (AND, OR, NOT, XOR). Core execution engine for most instructions.

FPU — Floating Point Unit

Handles floating-point arithmetic (decimals). Essential for scientific computing, 3D graphics, physics simulations, and audio/video processing.

Control Unit

Directs the operation of the processor. Fetches instructions from RAM, decodes them, and signals the ALU, FPU, and registers to execute the correct operation.

Branch Predictor

Guesses which branch of conditional code will execute next, pre-loading instructions before the condition resolves. Critical for pipeline efficiency.

L1 Cache (Per Core)

Fastest and smallest memory. Split into instruction cache (L1i) and data cache (L1d). Directly feeds the ALU and FPU with minimal latency (typically 4–5 cycles).

L2 Cache (Per Core)

Larger than L1 but slower. Acts as a second-level buffer between the core and the shared L3 cache. Typically 256KB–1MB per core.

L3 Cache (Shared)

Shared across all cores on the die. Much larger (8–64MB+) but higher latency. Reduces expensive RAM accesses by keeping frequently used data on-chip.

PCIe Controller

Integrated directly on modern CPUs, the PCIe controller manages high-speed communication to GPUs, NVMe SSDs, and other expansion devices — bypassing the chipset for lower latency.

Cache Hierarchy
Registers
L1 Cache
L2 Cache
L3 Cache
RAM
Storage
Each level is larger and slower than the last. The CPU always checks the fastest level first. A cache miss at L1 falls through to L2, then L3, then RAM — each step adding significant latency. Modern CPUs win or lose performance based heavily on cache hit rates.
LGA Socket & Package

LGA — Land Grid Array

Intel's socket design where pins are on the motherboard, not the CPU. The CPU has flat gold contact pads. Less fragile CPU-side; pins on socket are delicate.

IHS — Integrated Heat Spreader

Metal lid covering the CPU die. Spreads heat from the tiny die to the larger surface area where the cooler mounts. Thermal paste fills the microscopic gap between IHS and cooler.