CppCon 2026

How far can modern C++ push an emulator before performance stops being a C++ problem and becomes a systems problem? This talk is the final part of a CppCon trilogy about building an extremely fast Game Boy emulator in modern C++, moving from high-performance emulation techniques to the limits imposed by hardware, compilers, and CPU architecture.

The target is intentionally absurd but not arbitrary: a Game Boy emulator running Tetris at roughly 100 times original speed, about 6,000 frames per second. However, the goal is not to support every Game Boy cartridge ever made. This project deliberately specializes for one iconic game first, using the code paths Tetris actually exercises as a guide, while keeping enough design discipline to test other games later. That means questioning the architecture of the emulator itself: instruction dispatch, memory access, generated code size, cache behavior, branch prediction, compile-time computation, benchmarking methodology, and the tension between accuracy, maintainability, flexibility, and raw throughput.

This is not a victory-lap performance talk. It is a measurement-driven engineering investigation. Rather than treating 6,000 FPS as just a headline number, this talk treats it as a stress test: a way to force difficult design decisions into the open. Attendees will leave with concrete lessons about performance-oriented C++: how to measure methodically, how to specialize without losing control, how to reason about modern CPU behavior, and how to decide when an optimization is worth its cost.