Struct of Arrays (SoA)

The Data-Oriented way of organizing data. You have a single structure that contains multiple parallel arrays.

struct ParticleSystem { 
	std::vector<float> x; 
	std::vector<float> y; 
	std::vector<float> z;
	std::vector<float> velocity; 
	std::vector<int> id; 
};

• Layout: [x, x, x...][y, y, y...][z, z, z...]
• Pros: Excellent for SIMD. When calculating the sum of x, the CPU loads a cache line full of nothing but x values. This allows the hardware to pack multiple floats into a single 256-bit or 512-bit register (AVX/AVX-512) and process them in one clock cycle.
• Cons: Lower spatial locality for operations involving a single entity. Accessing all properties of “Particle 5” requires jumping to five different memory locations.