The Genius of the N64's CACHE Instruction

About this Video

• Video Title: The Genius of the N64's CACHE Instruction
• Channel: Kaze Emanuar
• Speakers: Kaze Emanuar
• Duration: 21:15

Introduction

This video explores the Nintendo 64's underutilized cache instruction, demonstrating how it can significantly improve a program's execution speed. The speaker explains the N64's cache system using an analogy and details various cache instruction modes, showcasing their potential for optimization and performance enhancement, particularly the "create dirty exclusive" mode.

Key Takeaways

• The Nintendo 64's cache instruction, rarely used in games, can drastically increase program execution speed under specific conditions.
• The speaker uses a city analogy to explain the N64's cache system, including the CPU, RAM, cache, and the RAM bus.
• Several cache instruction modes are described, including index invalidate, index load tag, index store tag, hit invalidate, hit right back invalidate, hit right back, and create dirty exclusive.
• The "create dirty exclusive" mode offers significant performance gains by allowing direct manipulation of cache data, bypassing unnecessary RAM interactions. This can lead to improvements of up to 20% in frame rate.
• The speaker discusses the potential of using cache manipulation for advanced techniques like creating a cache-based stack for operating system functions, eliminating RAM access entirely.